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EMERGENCIES & FIRST AID

FOR RAPTORS

Neil A Forbes BVet Med CBiol MIBiol Dip ECAMS FRCVSRCVS & European Specialist in Avian Medicine & Surgery

GREAT WESTERN EXOTIC VETS

Unit 10 Berkshire House,County Park, Shiverham Road,

Swindon SN1 2NR.Tel: ++44 (0)1793 603 800Fax: ++44 (0)1793 603 801

Email: [email protected]

Copyright of the entire contents of these notes is retained by the above lecturer. No part may be reproduced in any form without his prior consent.

Whilst we are always happy to advise our clients regarding their birds', or anyone who is prepared to travel to us with a bird and become a client of ours, we are unable to discuss the treatment of birds which are not owned by

our clients. We are however very happy to advise their vets, if they will telephone us.

Page 1 Copyright Neil A Forbes FRCVS 1996

CONTENTS page numbering is out due to deletion of legal paragraphs that are not applicable in Ireland

Introduction 3

Legal Implications 3-6

Health and Disease 6-8

Training to avoid illness 8

Recognition of Ill health 9

Shock Assessment and Therapy 9-12

Haemorrhage 12

Nutritional Support 12-16

Gut Obstructions 16-19

Damage to Surface of Head 20

Cere and Eyes 22

Wings 22-24

Avian bone repair + Physiotherapy 24-29

Feather and Beak Damage 30-32

Wing Tip Oedema and Blaine 32-33

Legs and Feet 33-36

Parasitology 37-39

Water logging, drowning, electrocution 39-40

Bites and Wound Management 40-41

Concussion, Crabbing 41-42

Chicks & Neonates 42-44

Breeding adults 44-47

Examination of the injured bird 48

Respiratory Disease 49

Fitting and Nervous Disorders 49-52

Poisoning 52-54

Accommodation 54-56

Hygiene for falconers / Rehabilitators 56

Assessment of viability 58-60

Rehabilitation Techniques 60

Acquisition of a new bird 61-62


Introduction

This course is not designed as a replacement for a falconer or rehabilitator having and using his or her own veterinary surgeon, but rather as an aid memoir of some of the major ailments which may befall birds, giving some indications of first aid treatment which might be administered prior to presentation at the veterinary surgeon. It is not possible to generalise about any given condition, each case varies and should be judged on it's own merits. For this reason no recommendation can be taken as gospel, and as such your own vet may not always agree with what is suggested here, this does not imply that he or she is wrong, they have the benefit of having seen your individual case and we have not. Any diagnosis and therapy based there on should be made by a suitably qualified veterinary surgeon.

Conversely many vets in general practice do not have great experience of dealing with raptors. In such cases benefit can often be gained by the vet telephoning some one who is an expert in the field, or by reference by them to standard texts which have been prepared for them eg. BSAVA Raptor Manual.

Before any rehabilitator or falconer needs to seek treatment for an injured bird they must first find the name, address and telephone number of one or preferably more vets within reasonable distance who will be able and willing to help.

Remember that even vets have families, and occasionally require holidays and time to sleep. Although every practice will give a 24 hour service, the other practitioners sharing this 'on call' facility may not be so conversant with avian patients.

Legal ImplicationsThere are a large number of sometimes complex pieces of legislation, which affect those who care for, keep, treat, and release birds of prey. In the South: Dúchas, 7 Ely Place Dublin administers the Wildlife Act 1976 and its subsequent amendments. In the North: the Environment and Heritage Service, Commonwealth House, 35 Castle Street, Belfast operates the Wildlife (N.I.) Order 1985. It is well worth buying copies of the relevant wildlife act for your particular jurisdiction and reading through them at length.

Protection of Animals Act 1911 (Applies in both North and South)

This act makes cruelty to animals (including tame or captive birds) a criminal offence, cruelty is defined as any action which leads to unnecessary suffering. Any wild bird which is taken into captivity for the sake of treating it, is a captive bird, (in the eyes of the law), hence any wild injured birds being cared for prior to release, are covered by this legislation as are falconer's birds. This includes not only directly harmful, or malicious acts, but also negligent omission. An offence is caused generally by the person responsible for the day to day care of the bird. Although the owner / employer might be also deemed guilty if they were aware that cruelty was occurring. Hence if a hawk was improperly tied to a perch, such that it was able to escape, or an ill trained bird was flown and lost, and if subsequently any ill fate, accident or starvation befell this bird you could be liable to prosecution. It also includes the manner of killing, and any operation performed without due care and humanity. In this situation if a falconer is seen to delay or fail to promptly and efficiently despatch a quarry species, or if a procedure is carried out on a bird which is painful, then one is open to prosecution. Defences such a 'anaesthetics are too dangerous' or 'I cannot afford to go to a vet' or 'my local vet doesn't know about birds' will not protect you in court.

CITES (1975) / COTES (1997)

Covers all species of raptors. The acts purpose is to control / restrict the trade (international) in endangered species. Applies to the purchase, offer to purchase, acquisition for commercial purposes, display to the public for commercial purposes, use for commercial gain and sale, keeping for sale, offering for sale, or transporting for sale. To undertake any of these the birds must be permanently identified with either a closed ring, or an identichip and the keeper must have an Article 10 licence. If the breeder is a DETR recognised breeder the bird may have a licence for life, which travels with it, otherwise a fresh licence is required for each change of ownership etc..


Health and Disease in BirdsOften birds which appear well (clinically healthy) are in fact suffering from a number of sub-clinical

diseases. At that point in time such sub-clinical infections are not important, as is demonstrated by the fact that they appear fit and well. However when such birds are stressed in any way eg. weight loss during training, accident or injury, or suffer some other infection the previously unimportant infections suddenly become significant and often life threatening.All living beings live in this balance between health and disease, a range of factors will affect the status quo of this balance.

BALANCE

HEALTHDISEASE

DISEASE

This delicate balance between disease and health is even more sensitive than in other species. What makes it considerably more complicated is that birds rarely demonstrate that they are poorly until they are severely affected by disease, often to the extent of being beyond treatment.

To make the matter even more complicated, a bird may be any of 'healthy' 'infected' or 'diseased'. In other words, very many birds will be carrying infection in their bodies, however many of these birds will genuinely not be ill at all. Any of the factors listed below may move a bird from one category to another, often with remarkably little effort.

Host Factors:-1. The birds immune status2. The birds inherent genetic resistance3. Age4. Sex

Environmental Factors:Page 4 Copyright Neil A Forbes FRCVS 1996

Healthy

Infected but healthyInfected

and sick

Host Factors

Environmental Factors

1. Composition of diet 2. Feeding Regime3. Accommodation4. Hygiene5. Interference from other birds (same or other species)6. Interference from keeper/trainer7. Climatic conditions

If the healthy but sub-clinically infected bird can be differentiated from the healthy bird then sub-clinical disease can be minimised or eradicated.Furthermore if the mechanism for the disturbance of this equilibrium can be understood then the host and environmental factors can be controlled in order to reduce the chance of clinical disease.An example of such a situation is seen when 'manning' a goshawk. Of all raptors the Goshawk is one of the most susceptible to Aspergillosis. One should control the environment by eliminating rotting vegetable matter from the proximity. It is often the stress of 'manning' which leads to clinical aspergillosis. In order to avoid this it may be prudent to give prophylactic treatment before and during the period of stress. Secondly when you do man the bird you do so as gently and as gradually as possible, or to fly a social imprint bird so as to minimise the stress caused to the bird during 'manning'.

Although this may lead to increased falconer frustration, in the long-term it may make the difference between a live responsive hawk and a dead one.

For rehabilitators every bird which enters your hands will be stressed, shocked and will probably also be injured, infected or diseased.

Training Birds the Kind and Healthy WayAs falconers we should be constantly making every effort to improve the quality of the birds which we are breeding and flying. Moreover we should be making increasing efforts to look after our birds better and reduce the risk of them becoming ill, and improving the care they receive if they become ill.

Stress - what is it and why is it bad for our birdsWhen a bird is frightened, the brain reacts by telling the adrenal gland to release adrenaline and cortisol (i.e. steroid). Cortisol travels to the liver and mobilises glucose, to provide energy to fly away from the frightening situation. As many people will be aware, steroid although useful on occasions, can have unpleasant side effects, even when it is steroid of a natural origin (i.e. from within the bird's own body).

Our concern in this situation is that steroid reduces the birds 'immune system' i.e. the bird's ability to react against and fight off infection.

In a natural situation, a bird meets a frightening situation, its body reacts to that, it flies away and everything returns to normal. The short peak in cortisol has no significant effect on the bird's immune system. However when a bird is in training, typically the bird cannot fly away from the frightening situation, so the fear continues. The body’s response is to continue to produce cortisol, the outcome is a prolonged depressive effect on the bird's ability to fight against disease.

Every day we and our birds are surrounded by potential infection, and all the time we are defending ourselves against it, and fighting it off. If our bird's immune system is compromised, it cannot fight of infection, and the bird may well succumb to a common, perhaps ubiquitous organism such as Aspergillus fumigatus, the fungus which comes from rotting vegetable matter, and is in the environment all the time.

So what can we do about this? The simple answer is to minimise stress to our birds. It is true for most birds, in particular the Accipiters, that the most stressful event in a falconer’s bird's life is training. Other potential stressful times may arise during the moult, breeding, transport, or if they get lost whilst out flying, and spend a few days out loose.

So what makes training stressful. Untamed birds, are not accustomed to being close to humans, and perceive us as a threat. Reduction in weight is in itself a stressor, the more the weight is reduced the worse it is.

So during training the key improvements can be:-

Allow the bird to become accustomed to your presence, prior to starting training.Train the bird very gradually, do not force yourself on it to quickly.Reduce weight only slowly, and minimise the total weight loss required as much as possible.

Such advice is easily applied to a falcon or Harris hawk, but no so easy with an Accipiter.There is of course another option. Why not fly an imprint. Imprinting a bird correctly is not necessarily easy, it is very time consuming, and can go wrong. But if you get it right, that Gos wants to be close to you, on your fist. It is not frightened out of it's skin and trying to bait away from you all the time. as the bird is responsive, you do not need to reduce the weight to any significant extent.

So to conclude. End result, a healthy bird, which is less stressed in training, is less likely to get ill as it is not stressed. It will fly at a higher weight, fly stronger and catch more quarry.


Side effect - it is less stressful for the falconer to train and keep the bird. You will be happy, more relaxed and less likely to end up with a divorce, coronary or depression during the training, illness and subsequent death or your over stressed immune compromised goshawk.

Recognition of Ill-HealthAll bird keepers should appreciate that birds hide the signs of illness, especially in comparison with cats, dogs and humans. They have developed this ability over the centuries as a defence from predation. A predator will always single out the weak or ill individual. To reduce the chances of predation they disguise the fact they are ill for as long as possible.

By the time that a bird appears ill, it is approximately 70% dead, further more by the time an injured wild casualty is handed in it is about 90% dead.

In view of this one should be aware of several important points.Firstly that the very keen, thorough and regular observation of your birds is paramount. For the beginner,

it is crucial that the signs of good normal health are recognised and identified. Once you know your bird well in good health then you will immediately realise when it is ill. At the first sign of ill health, some action should be taken, if the condition is left, then it may well deteriorate rapidly beyond the point of recovery.

If birds are in an exclusion breeding aviary, full observation and examination maybe more difficult. However this should be no excuse, the aviary should be designed such that all areas of the aviary can be fully visualised. Vets are confronted by a situation where the bird was not seen for 24-36 hours, in hind sight because it was ill and on the aviary floor. This situation should never arise. Similarly a bird should never be left tethered to a perch, when it is not being constantly monitored. Birds do get alarmed bate off, tangle in their jessies, or end up astride their block. A tethered bird should never be left in an area where it is likely to become startled in particular by predators, be they the four or two legged variety. (No bird should be tethered if it is not being flown daily), unless during training, or an imprint semen donor.

Once a bird is seen to be ill, do not necessarily assume you know what is wrong, but seek expert advise and help, whether this be from a genuine expert falconer or a veterinary surgeon experienced in the field.

Any bird which is ill, including all wild casualty birds are likely to be suffering from shock. In view of this the bird should be handled as little as possible, and should be treated for shock. In the case of wild birds do not be fooled by the response of the bird, some species will always react aggressively, such as goshawks, kestrels, whilst others such as red kites and buzzards, will react like gentle babies, hardly moving at all. Having made allowances for these species variations, the quieter and less responsive any injured bird is, the more shocked and critical it is likely to be.

To the inexperienced but conscientious wildlife rescuer there seems to be an inherent desire to cuddle and nurse an injured or orphaned creature. Such temptations must be rejected as a matter of great importance. It cannot be over stressed that that wild creature is not accustomed to close human contact. Any act of handling, especially if prolonged will only serve to increase the level of shock and reduced the overall chances of survival.

Each bird must be assessed on its own merits, but it is believed that the initial examination of the bird, whether it be by a veterinary surgeon, falconer or rehabilitator should be simple, brief and non stressful to the bird. Shock treatment should be immediately instigated and a full examination only made once the bird has recovered from the initial shock.

SHOCK"Shock" is a condition which arises from a pronounced drop in circulating blood volume, if untreated it is likely to lead to circulatory collapse and death. It will arise after haemorrhage whether internal or external, tissue damage, pain, or psychological trauma. The situation will be made worse if the bird is subject to further pain, fear, loss of body heat (exposure) dehydration or hunger.

In view of this a shocked bird should handled as little as possible, and the stress of various different treatments for shock should be compared with the benefits achieved.

Some authors recommend the use of intravenous or subcutaneous fluid therapy as well as glucocorticosteroids. In the author's experience, unless the bird is in need of immediate euthanasia, the best treatment regime is to give the bird 1% of it's approximate body weight, of warm glucose saline (Lectade or equivalent) or hartmans solution (lactated ringers solution), by mouth using a crop tube (see later for method). This procedure should be practised on dead birds during the practical, then on a healthy bird, prior to having to use it on a sick bird, it is usually a two person task.Page 6 Copyright Neil A Forbes FRCVS 1996

The crop tube itself is easily made from a piece of fine plastic tubing ('giving set tube' available from any vet), pushed onto a suitable sized hypodermic syringe (without a needle).

One helper holders the bird firmly by the shoulders at the same time locking the legs between fingers four and five so that the legs are controlled. The other person then takes the birds head in their left hand (if they are right handed), opening the beak with the fingers of the right hand. The index finger of the left hand is then inserted in the angle of the jaw. Do not hesitate and put the tip of the finger in, it will be bitten (painful) instead place the finger firmly the whole way across the roof of the mouth from side to side. The tongue is clearly visualised, and at the back of it the lemon shaped opening of the glottis (entrance to the wind pipe) can be seen.

Lubrication of the tube will often be helpful, using K Y Gel or your own saliva. The head and neck should be extended, the glottis avoided, the tube is passed down behind the tongue, and into the crop. The position of the tube in the crop can often be seen by gently moving it up and down, and at the same time watching the area of the crop on the front of the breast.

The plunger of the syringe is then slowly depressed, whilst at the same time, the inside of the mouth is observed, if excess fluid is administered, it will be seen welling up inside the birds mouth. If this is seen then one should stop immediately and release the birds head. Usually the bird will swallow and shake it's head and any excess fluid will be dispersed.

On Going Assessment Protocol for Injured Wild Birds

Initial Clinical Examination

Euthanasia

Euthanasia

Euthanasia

Euthanasia

Treatment of ShockReturn to the Wild

Rexamination Further

S u p p o r t i v eTreatment

S u r g i c a l / M e d i c a l Treatment

Supportive Treatment

Rehabilitation

E u t h a n a s i a

Maintain in Captivity

Return tothe WildEuthanasia

SSupportive

Surgical / Medical


There is a temptation particularly in a thin or starved bird to start pumping nutritious fluid or foods into the bird immediately. It is important that hyperosmotic (i.e.. fluids which are stronger than saline) are not placed into the gut until the shock has first been controlled. If this is done then some food may be absorbed, but more of it will in sit in the gut acting as a suction pump, drawing fluid from the circulation, back into the gut. This in turn increases the bodies state of dehydration, thereby leading to increased shock and likely untimely demise.

Once the fluids have been administered the bird is wrapped in a dry towel or equivalent and placed with it's head protruding from the towel, on a heated pad, in a closed cardboard box. If a heated pad is not available, then a hot water bottle, or other bottle filled with hot water may be used. Alternatively the box may be placed next to a warm radiator. The bird should then be left in the quiet, dark and warmth for two hours. Everyone should resist the temptation to examine the bird during this period. If active infection or haemorrhage are seen then these should also be controlled at this initial stage.

After two hours the bird should be re-examined, on this occasion a more through examination should be possible, such that the extent of the injuries, and hence the prognosis can be evaluated. The bird is then assessed methodically and rated schematically as per the flow diagram (previous page).

If the bird is still weak or shocked fluid therapy can be continued safely, giving up to 4% of the birds body weight as additional fluid, within the first 24 hours, if the bird appears dehydrated (dry non elastic skin) further fluids can be given. Such birds may benefit from augmenting this fluid with other liquid nutritional supplements (see next section). Birds, as a result of their small size have a very high metabolic rate, in simple terms they burn up more energy more rapidly, in comparison with cats, dogs and humans who can live off body fat for some time.

They have a higher normal body temperature than mammals, and especially when stressed benefit from raising the ambient temperature to 70-80 oF, for a period of 24-36 hours.

As previously mentioned heat may be supplied by a heated pad, (available from veterinary suppliers, similar pads are used by gardeners for early germination, and 'home brew' beer and wine makers). Alternatively hot water bottles or infra red lamps. A note of warning, some modern infra red lamps, because of Health & Safety Regulations are now sold with a coating of "Teflon" (similar to that used in non-stick cooking pans) so that if the bulb shatters, the glass does not fly everywhere. Overheated "Teflon" emits fumes, which are extremely toxic to birds, killing them in minutes, so beware.

Haemorrhage

Birds blood volume lies between 9 - 13% of it's body weight being a higher percentage in smaller birds. Particularly in small birds a relatively small blood loss can be rapidly fatal. For this reason haemorrhage should be effectively controlled as quickly as possible.

The one good aspect of avian haematology is that if the blood loss can be suppressed, then the rate at which new blood is formed and pumped into the system is much faster than with a mammal. The majority of the blood loss will be fully replaced within a fortnight, as compared to several weeks in other species.

Specific situations in which haemorrhage is experienced, are described below. At all times a bird will only continue to haemorrhage if the blood pressure inside the blood vessel is greater than that outside. Hence the main aim of haemorrhage control is to increase pressure on the outside of a wound, this is either naturally by clot or scab formation, or artificially by applying local pressure.

Some aids to haemostasis can be used, if the blood is appearing from a deep wound then a pressure pad, supported by a light weight bandage, dressing or initially finger pressure. In a shocked bird breathing may also be laboured, in such situations a dressing placed around the body, in particular if it is too tight can prevent it from breathing. If the point of the bleeding can be seen then a haemostatic swab (Haemo Swab or Kaltostat), can be applied with pressure. Alternatively a caustic pencil (available from any chemist), alum crystals, potassium permanganate crystals (as supplied in the first aid kit) or ferric sulphate solution can be applied to the specific area. These methods of caustic haemostasis should only ever be used on a pin point area of haemorrhage. If the bleeding can be seen to be coming from the free end of a blood vessel, then on occasions this can be grasped with a pair of forceps and a knot placed around the end with a piece of clean cotton. By preference the cotton should be sterile, however in the emergency situation anything will do. It can always be replaced later on, once the bird is stabilised. As a last resort if one is without such proprietary aids, then clean cobwebs gathered from the vicinity may be placed over the area, and then covered, these will encourage a blood clot to form. If such a method is used, a topical antibiotic wound powder should also be applied. The powder will often help control the haemorrhage and at the same time prevent any infection (as supplied in first aid kit).

Nutrition and support for the injured bird.

Sickness and injury weakens the body's defence mechanism. The latter effect is felt not only by the immune and circulatory systems but also by the digestive tract and the whole metabolic process. It is for this reason that it is wise not to introduce an invalid bird to a radically different diet. As a general rule the use of the Page 8 Copyright Neil A Forbes FRCVS 1996

bird's normal prey species, and hence food type should be used where ever possible. The one exception to this rule is that a normal raptor, traditionally fed just once daily has to wait until after casting before it can be fed again. Although casting material is required on a day to day basis, it is certainly not required during a period of nutritional crisis. As such casting can easily be left out for several days, this will allow frequent small feeds, at 2-3 hour intervals.

As mentioned in the previous section on shock treatment, there are times when benefit is gained from giving liquid food. This is particularly the case when a bird has been vomiting. If a bird has been highly stressed, and will not feed voluntarily, then liquid food may be employed until the bird has regained some strength.

The composition of any supplemental food, should be kept as close to natural as possible. The introduction of milk, or cereal products should be discouraged, as these in themselves will present a new and additional challenge to the digestive system. There are a range of convalescent type diets which are produced and used in humans, cats, dogs and birds. The initial inclination may be to use a diet designed for birds. However one will often find that these are designed for herbivorous birds and would be totally unsuitable for raptors.

The liquid diet used by the authors is a convalescent diet produced for cats & dogs and stocked by most small animal vets (Hills a/d), or bird equivalents (Polyaid, Critical Care Formula, Day One).

If one is encountering problems with a bird keeping a liquid diet down, there may well be a medical reason for this, such as aspergillosis, sour crop, capillaria, candida, pox, frounce a twisted or blocked gut or a bacterial infection. In this circumstance an immediate trip to your vet is indicated. Any delay in presentation of a vomiting bird may well prove fatal, this is particularly the case in falcons.

Remember that placing an uncustomary food in front of a bird may well in itself lead to loss of appetite and anorexia. An example is the wild injured raptor who would not recognise a day old chick from strawberry. If feeding day old chicks to injured wild birds at least skin the chicks first, and gentle force feeding may be required initially.

The smaller the bird the greater the percentage of it's body weight it must eat daily in order to maintain body condition.

Food Required as a % of body weight

100 - 200g 18 - 25 %200 - 800g 11 - 19 %800 - 1200g 7 - 11 %4000 -10000g 3.5 - 6 %

(From Graham & Halliwell, 1986)

The overall food requirement of a resting bird will be increased in situations of stress, injury and illness. For example the fracture of a bone may increase the food requirements by up to one third, allowances for such increased requirements should be made. Remember that hypoglycaemia, as discussed more fully in the section on fitting, can easily occur not only in a starved wild bird, but also in any injured bird which is a bit off it's food. Precautions should be taken to avoid this.

If faced by total disaster, as a result of a bird refusing or being unable to either tackle food or keep it down, bare in mind that food can be provided by crop tube, subcutaneous or intravenous fluids, your veterinary surgeon can assist with any or all of these.

Although a fit and well bird will usually acquire all its fluid requirements via it's food, if the bird is sick, injured, tired, over hot etc., it is likely to require additional fluid. It is good practice to always provide birds with water, however when a bird is ill, 'good practice' becomes an essential part of husbandry.

However one should beware that on occasions birds can drown in even the shallowest water, this may even be more likely when the bird is weak or ill (see section on drowning).

General Points Relating to Feeding

General Aims :- to feed a diet as similar to the consumers natural prey species that the bird would enjoy in the wild, whilst at the same time ensuring the correct food quantity , quality, wholesomeness and storage methods.

Feeding Neonates :- the most important realisation is that chicks are "immune incompetent" for the first ten days of their lives. In simple terms this means that they are very susceptible to infections, and find it hard to fight them off. Bearing this in mind the hygiene relating to the preparation of chicks food must be of the highest standard. In our experience the best way of tackling this problem is to feed a probiotic (some are better than others), for the first ten to fourteen days of life. A probiotic is made primarily of "good & helpful" bacteria (Strep faecalis & Lacto bacillus), which will colonise the gut thereby avoiding the swamping of the gut by pathogenic (i.e. harmful) bacteria.

The composition of chicks diets is far more important that that of adult birds. It cannot be over-stressed that the diet must consist of whole carcasses, and not simply muscle (i.e. meat). Many breeders are aware that one should be careful of giving roughage to young birds, however bone is not roughage, not only it can but it must be fed. The


whole carcass should be pulverised in a mincer such that no fragments are too large. Calcium deficiency will be considered in greater detail later.When young chicks are parent reared then the parents will usually carefully pluck any food items until such time as the young can cope with the casting. One situation to be careful of is when one is using a foster parent of a different species as she may not fully appreciate the capabilities of her fostered young. The result can be that she gives them too much casting at too young an age. More commonly it is the unsuspecting hand rearer who gives excess casting. It is rough casting such as rodent fur which is found to be most troublesome, furthermore some species such as the merlin, seem particularly prone to the problem. It is certain that no merlin should be given any fur until it is at least 18 days old. Most chicks can and should manage a small amount of feather from day ten, but no fur until considerably later. If a problem does arise it is demonstrated as an impaction. The chick slows in its weight gain, has a poor appetite, and may have a swollen hard lump in it's abdomen (proventriculus). If the situation is realised at an early stage then repeated crop tubing with fluid therapy every 2-3 hours will often soften the casting and facilitate it's return. If however the situation is advanced, then surgery is the only option. The prognosis is not wonderful as one is operating on a small, weak and ill youngster.

Deficiencies as commonly seen in chicks:- Calcium is the commonest and most significant deficiency which is encountered. The result is a chick which are initially normal, but the becomes weak, poor appetite, cannot stand and may eventually suffer from fits. Calcium deficiency may arise for one of several reasons. Firstly the egg itself may have been deficient in calcium. It sounds bizarre that a female bird should manage to coat an egg with a large volume of calcium (it's shell), but fail to put sufficient calcium in the egg itself, however it does occasionally occur. A number of factors are important in the metabolism of calcium in the body. Firstly the diet must have sufficient calcium in it, secondly the bird must have sufficient activated Vitamin D3 in its body to absorb the calcium from the gut, and thirdly the kidney should not be so damaged that all the calcium is lost from the bloodstream before it can be used. Activated vitamin D 3 can be supplied in the diet, however more typically Vitamin D is supplied, this requires the action of ultra violet light (i.e. part of day or some fluorescent light) to convert it to the active form. Typically calcium deficiency of eggs arises when additional calcium is required such as for species with large thick egg shells such as secretary birds, or were the adult birds are suffering from kidney disease (which is not uncommon in elderly birds). The consequence of this form of deficiency is chicks being born with bent keel bones (chest or sternum), or swollen painful ends to the long bones. Although if the condition is recognised additional calcium can be given, but by this stage often the damage has already been done. Alternatively if large whole carcasses are fed to parent reared young, there may be so much food that the parents do not bother to feed bone, or the bones may be too large for the young birds to ingest.

More often calcium deficiency occurs due to a deficiency in the chick’s diet. The signs of deficiency are usually not seen until the chick is 14-21 days old, and may not even be recognised until considerably later. The bird is weak, has a poor appetite, weight increase ceases, is unable to stand, often the feet rotate inwardly. In severe cases the bird may show violent fits. If the condition is recognised, the bird should be x-rayed to investigate the severity of the damage. Many birds are already beyond repair, others will respond to either just a change of diet, some will require bent legs etc to be straightened.

Vitamin B2 (Riboflavin) Deficiency :- Vitamin B2 should be present in sufficient levels in any quality mixed diet, which has not been stored for an excessive period. Deficiency is demonstrated by an inward curling of the toes, typically seen within the first 14 days of life.The problem is rapidly reverted to normality by supplementation by injection or by mouth with B2.

Vitamin E / Selenium Deficiency :- This results in a backwards tilting of the chicks head, to the extent that the chicks head may be upside down. The condition is commonly termed 'star gazing'. It is seen most commonly in chicks fed on food which has been stored for too long, in particular if that food has a high fat content. Treatment is initially by injections of vitamin E and selenium, followed by further supplementation of the diet.

Supplements in Birds Diets:- All bird keepers will now be well aware that there are a whole range of different supplements which are available for addition to birds diets. The authors opinion is that supplements will only be required in exceptional circumstances if the birds are fed a good diet as a routine. Moreover supplements should not be used, 'as a let out', so that one can then feed a sub standard diet. A good diet will be varied, will be different depending on the size and type of bird being fed. Such a diet might well include rats, mice, day old chicks, ‘grown ons’, quail, rabbit, pigeon, squirrel etc. It is quite permissible to feed day old chicks (with yolks removed most days), on 4-5 days of the week as long as improved food is given to 'pep them up' on a couple of days as well. On all occasions feed whole carcasses, i.e. meat and bone, never remove meat from the carcass and feed that alone. It is appreciated that in some temporary situations the alternative supplies may dry up depending on time of year, availability etc., at such times it is sensible to use a supplement. Supplements should be used at all times of stress, eg. moulting, breeding and training.When choosing a supplement, pick one which has been carefully , correctly and accurately formulated with birds in mind. Whilst using it follow the manufactures recommendations. Do not follow the hypothesis, that if a little bit is good, a little more is better, this is a dangerous and erroneous philosophy which can lead you sadly astray.

Dehydration :- Any bird may become dehydrated. Although it is generally accepted that few raptors drink, some do, especially when ill or exhausted. Chicks may become overheated or dehydrated as they are not good at moving into the shade, or controlling their body temperature. If after mincing, chick food is stored in a fridge, then


it will, to some extent dry out. In view of this it is often necessary to add additional fluid (Hartmans, lactated ringers soln., or glucose saline) to the food. In particular if a birds mutes are at any time more watery than usual it is essential that water is available. All raptors should have water available at all times. Remember that a normal raptors diet is at least 85% water, if the bird is not eating, not only it is consuming no food, but more importantly it is taking in no water.

Food Requirements:- It is important for the keepers of birds, in particular those treating or looking after different species from time to time to appreciate the degree of variation in food requirements, dependent on the size of bird one is feeding.

Problems Encountered with Feeding Adult BirdsSource of food:- Irrespective of the food type, it is obviously essential that one is 100% certain as to the quality , source, method of killing, freezing and storage of the food. Any ex-wild source of food eg. pigeon, game, etc. must be considered to be potentially infected. Such birds can carry bacterial infections such as Tuberculosis, Salmonella, Campylobacter or virus infections such as Paramyxovirus, Adenovirus or Rotavirus. Or alternatively they may have been poisoned eg alphachloralose, mercury, lead, DDT. Any wild sourced food should be in good body condition, have been caught and killed by physical means, and on examination of the carcass should look in all respects to be thoroughly wholesome and free of disease. It is crucial that the abdomen of such birds is always opened and the surface of the liver checked. If any small white spots are present on or in the liver, (often indicative of avian tuberculosis) the whole carcass must be rejected.

One should be wary of feeding road traffic casualties as one does not know why the animal or bird was so slow that it got hit, perhaps he wasn't feeling too good that day !! Any food such as rats mice squirrels or foxes, is less likely to cause any infectious disease to your birds. The reason for this is that most pathogens will only affect one family of animals, ie. a rodent virus is highly unlikely to affect birds. Conversely feeding any avian derived foodstuff will always carry with it a potential risk.

In recent years we have encountered several outbreaks, in particular of virus disease, (eg. Adenovirus & Rotavirus), where perfectly healthy commercially sourced quail, day olds, turkey poults etc., have been fed to healthy raptors which have then succumbed to disease and in several cases died. The problem here is that many viruses can be harboured by one species (eg. day old chicks), with out causing them any harm, ie the chick looks and is healthy, but when the chick is eaten, the raptor is affected. Sadly although the virus did not harm the chick it may conversely be deadly for the raptor. There is no way of predicting or avoiding this, albeit rare, problem except by avoiding feeding any avian derived food.

Pigeons form a special risk to raptors on account of their high incidence of Trichomoniasis (frounce). Many falconers believe that if they only feed the breast there is no risk. Sadly this is not true. Stressed, old, young or ill birds will be most susceptible. Birds in perfect health may avoid the infection, otherwise most wild peregrines would suffer badly. However no risks should be taken, all pigeon which is fed should be frozen completely and thawed before feeding. The duration of freezing is unimportant. In some parts Paramyxovirus, Avian Tuberculosis and Falcon Herpes virus may all also be contracted from fresh or frozen pigeons which are fed

Rabbit & pigeon :-many falconers feed ferreted, rifle or shotgun shot rabbits or pigeon. The author would strongly implore that shotgun killed quarry should never be fed. One is aware that some falconers have for many years fed such food, and by feeding an increased level of casting have avoided lead poisoning. Some keepers swear they can find and remove every pellet. However in view of the number of lead poisoning cases that we still encounter, I can assure you it is not worth the risk. A further risk which cannot be avoided, but that one should be aware of, is encountered when feeding rifled or ferreted rabbit or pigeon. One is aware that on occasions some poor shot will have peppered such an animal at a prior date without killing it. So although you know that you put no shotgun pellets in the quarry, they may already be present. The food source is good and healthy and it is unreasonable to avoid it in view of the low risk, however one should be aware of it, so that if any signs consistent with lead poisoning are seen that immediate action can be taken. The signs of lead poisoning are of weakness of legs and wings, inability to stand, often grasping the feet each in the other, inco-ordination, poor appetite, green mutes, and weight loss, or any nervous signs. If these signs present, the bird should immediately be seen by a vet, and it is important that you do not insist to the vet that there is no possible chance of lead poisoning.

Rabbit :- just occasionally when feeding larger species on rabbit or hare a problem can arise. If the bird is sufficiently greedy it may take the whole thigh (femur) bone of the rabbit. On many occasions the bird will cope with this, however sometimes it will wedge sideways in the crop or proventriculus. This may cause a perforation of the gut lining or an obstruction. The recommendation for such sized birds is to break the femur before feeding the carcass, if the bone is taken in two sections no problem will arise.

Too Rich a Living can Kill :- Atheroschlerosis is a common cause of death in many caged birds. The condition is similar to the hardening of the arteries which occurs commonly in humans. The condition will arise predominantly in situations of excessive eating, in particular a high fat diet, combined with a lack of exercise. There is never any indication that the bird is ill, it is simply found dead in the aviary. The condition is commoner in older birds, in particular female birds after the breeding season, due to the high level of circulating fats which were mobilised in order to fill the yolk of the eggs. It is known that the tendency towards the disease is hereditary. Most Page 11 Copyright Neil A Forbes FRCVS 1996

importantly however is the fact that if the condition could be predicted or diagnosed prior to death the pathology is totally reversible, simply by reducing the fat content of the diet and by exercising the bird. Initial exercise should be gentle, and only gradually increased. A blood test revealing a high blood cholesterol level may indicate that a bird is at risk.

The condition is best avoided by ensuring that food given is not excessively fatty. Old spent laying quail, mature fat laboratory rats/mice and egg yolks are the main culprits. Furthermore it is important that birds are not overfed, becoming too fat. When feeding in a breeding aviary, food is best supplied in a draw system, rather than a shute. In this way if excess food is given, (as long as it is not taken and cached), it can be removed rather than sitting around on the floor of the aviary gradually going off. The positioning of the food drawer in the aviary is also important, it should not be indirect sun light in the heat of the day, as this would encourage food to go off more quickly. When you feed your birds daily, watch their reaction they should come straight down to feed. If they do not, they are probably not very hungry, hence give them a little less food that day.

Exercise, as stated above is important. In particular, if it is practicable, it would be advantageous to take birds out of breeding aviaries at the end of the season and fly them for a short period, if only a few weeks, in order to blow out and clear their arteries.

Feeding the Bird Which is low in Condition :- Many falconers have an obsession about giving casting each and every day. As all keepers should be aware it is important not to feed a bird again until it has brought up the casting from the previous day. If you have a bird which is low in condition, you do not want to have to wait a full day before you give a further meal. In this situation it is quite permissible if not essential that you do not give any casting. Instead you give a small meal of finely chopped meat, perhaps with a little added saline. As soon as, and not before, the bird has put it's crop over it should be given a further small meal. I would hope that all falconers would be aware of the condition of 'sour crop'. If food has passed from the crop into the proventriculus (stomach), stomach acids will act upon it, aiding the digestion as well as preventing any bacterial action on the food. If conversely the food stays in the crop, it is no longer in your fridge being kept nice and cold, instead it is at body temperature, and yet has no acid acting on it to prevent bacterial decay. In short the food goes off very rapidly, causing the production of toxins (poisons) which very rapidly kill the bird. If your bird is slow to put it's crop over, then a small volume (0.5% of the birds body weight, (ie. 5ml for a 1 Kg bird), of saline should be given by crop tube. This will usually quickly result in the crop being put over. If it does not, and the bird does not throw the crop back of it's own accord, then the food must be removed by milking it back up from the crop. This can be a risky procedure as any fluid present in the crop, will return as the meat is brought back up and the fluid may go down the windpipe causing a fatal pneumonia. Whatever the outcome the bird will need veterinary care and antibiotics, the food would be best removed by your vet with the bird anaesthetised and entubated.

Feeding the Vomiting Bird :- Vomiting may arise in raptors as a consequence of a whole range of different conditions. The situation will almost inevitably require veterinary care, although a few general points are mentioned here. A bird which is vomiting should not be immediately offered more food, even if it is loosing weight fast. If more food is given the vomition will continue. Instead the bird should be allowed to settle for an hour then a small volume (0.5% of it's body weight ie. 5ml per 1 Kg bird), of slightly warm (hand temperature) saline (eg. lectade) should be given by crop tube. The bird should be placed in a warm dark quiet area and allowed to settle. If the fluid is kept down, it should be repeated once more two hours later. If that is retained then a further two hours later, a feed with the same volume of a liquidised food should be given by crop tube. Most standard cat and dog vets will stock suitable liquidised convalescent diets, examples are Hills a/d or bird forms (Polyaid, Critical Care Formula, or Day One). The liquid food is repeated every 2 hours on 3-4 occasions, before the first meal of finely chopped beef (or similar). If the bird is not keen to take the meat, it is not yet ready for it. As stated previously a bird may vomit for many reasons, from simple matters such as travel sickness, to more serious situations such a Aspergillosis. Unless the situation is truly straight forward, and the bird immediately responds, veterinary care should always be sought.

Feeding the Inappetant Bird :- Frequently one is faced with a bird which is low in condition, which you know should be eating, which is however not wanting to feed. Many conditions can cause this. Any mouth (eg. frounce, Capillaria, Candida), oesophagus/crop (eg. local irritant, bacterial infection, sour crop, pox virus), stomach (eg. impaction, infection) or air sac (eg aspergillous, air sacculitis, egg peritonitis) or septicaemia (ie. blood poisoning) condition will lead to a depressed appetite. Sometimes the bird will simply not eat, on other occasions the bird attempts to eat, but then flicks it's head all the time and brings the food back. Any such bird will need to be seen by a vet, an accurate and specific diagnosis made and the condition treated.

Bird which is low in weight, or not putting weight on in relation to it's food intake:- This situation is common. Either a bird may be taken out of an aviary after a moult and not be as heavy as it should be bearing in mind it's ad libitum feeding, or the weight loss may be noticed as a consequence of daily weighing. Again a range of conditions may be responsible. The immediate reaction on the part of many keepers is to assume the bird is suffering a parasitic condition. Even if this is so, the keeper will probably then worm the bird with a standard wormer, such as fenbendazole (Panacur). The problem is that such a wormer only treats one form of parasite (ie roundworms), so even if the problem is parasitic, the situation may continue unchecked. It is far more sensible to have a mute (faeces) sample checked, to see if it is a parasitic problem, and if so what is the correct medication to use. Furthermore if the cause is not parasitic infection one can immediately take action to find the real cause.

Weight loss may be caused by any illness. If it is gradual loss over a period of time the most likely causes will be parasites, bacterial gut infection, aspergillosis (even in the absence of any respiratory signs) or tuberculosis. Expert veterinary care is required, to differentiate and treat accordingly.Page 12 Copyright Neil A Forbes FRCVS 1996

Feeding Birds and Travelling :- Birds should not be fed directly before travelling, in particular if they are not used to travelling. If one is talking about an experienced flying bird, who is used to travelling, known not to suffer from travel sickness, then fair enough he may be fed up after a kill and allowed to travel home.

For a bird such as a Peregrine, we would advise giving a cast free meal 8-12 hours before travelling. The danger is that any bird with a stomach or crop full of food or casting, may regurgitate during the journey. This is particularly dangerous if the bird is hooded. However even without a hood, the bird can choke and die in a matter of a few seconds. Conversely a bird should not be starved for a long period before travelling. The smaller the bird, the less time they can manage without food. Many of the essential nutrients are not stored to any extent, or are unable to be rapidly mobilised, by the bird. Examples are glucose and calcium. Nervous birds, who are particularly sensitive to stress are prone to calcium deficient fits if food has been withheld and the bird is then stressed. In particular if goshawks are to be transported long distances (or undergo any other major stress), it is advised that they should be given additional calcium supplementation beforehand. In the authors experience the most effective product for this situation is 'Nutrobal' (Vetark). Even a single dose of this powder by mouth prior to such a situation is likely to be effective.

Casting in Adult Birds :- This has already been mentioned with chicks, however problems may even arise with adult birds. If birds are tethered in mews, whose substrate is peat, wood shavings, or sawdust, then as the bird eats food, if the food has fallen on the ground, peat, wood shavings etc may also be ingested, leading to an impaction.

Obstructions I have KnownIt often amuses and surprises members of the public, just how large a piece of meat may be consumed by a greedy bird of prey. Although the bird is usually non the worse for it, there are sadly occasions when large or unusual objects that are ingested, do cause the bird some illness.Over the years, we have in our practice seen a number of common and some more unusual upper intestinal foreign bodies, which have required treatment. We hope that by bringing these to falconers notice, some at least may be avoided in the future.

Birds of prey, excluding owls posses a crop. This is a non glandular, dilation of the oesophagus, which acts simply as a storage vessel for food prior to it advancing into the stomach. The presence of a crop allows a bird to gauge after a kill, taking on board more food than the stomach can immediately handle. In this way a bird may only have to kill once in the day, but that the volume of food ingested can keep it going all day. An obstruction may arise because a large non digestible object is ingested, or when something occurs to stop the normal progression of food along the gut. In the latter situation, the food is obstructed in it's transit, rather than being an obstruction, but the result is similar.

'Sour Crop' is a common and rapidly serious condition. If meat stays in the crop longer than usual, it will rapidly start to go off. The meat is being maintained at 38 - 40oC, with no gastric acid or enzymes present to prevent bacterial multiplication. 'Sour crop' occurs most commonly when a bird is given a large crop, especially if it is unwell, traumatised or in low condition at the time. The commonest time for this to occur, is when a bird has first 'entered'. The falconer may well have dropped the bird's weight a little bit further that day, to encourage it to 'enter', then once it has killed he or she is so pleased they want to reward the bird, and so they allow it to take a really large crop. Such an over full crop, for a bird which has flown hard, and may well have been in low condition, is often more than it can cope with. The crop sits there, ballooned out, looking very uncomfortable, until either the bird becomes ill, or if one is lucky it is passed over, or the bird brings the food back.

Our advice is never give a bird which is low in condition, traumatised, ill or shocked a large crop. Give just a half crop. If the bird is ill, and you are attempting to increase it's weight, then give a small crop, but without casting,. In this way, as soon as the crop empty, more food can be given. So you can increase the food consumed, without any risk to the bird.

If your bird is slow to put it's crop over, your first step should be to administer 5 - 10ml /kg of saline by crop tube. A little lubrication will often speed the passage of the food without any further problems. If this is not effective, and the crop is still unmoved after 6 - 8 hours, you should contact your vet as a matter of urgency. The bird should receive protective antibiotics, fluid therapy, and the food must be removed from the crop. Removing the food is not a straight forward affair. If food is simply milked back up from the crop, using finger and thumb either side of the neck, there is a chance that any fluid (including chick yolk etc.) present in the crop will trickle down the bird's wind pipe (trachea), causing what is termed 'an inhalation pneumonia'. This is a very serious and usually fatal condition. Instead the bird should be anaesthetised by a vet, and an endotracheal tube placed in the trachea to prevent inhalation of crop contents, and then the food massaged back from the crop into the mouth. It is however often easier, and with less risk to the bird, to open the crop from the outside (once the bird is anaesthetised), and remove the crop contents from the breast, before closing the crop wall. Antibiotics and gut activating drugs (eg. metoclopropamide), as well as fluid therapy must then be administered. Sour crop is a common and generally preventable condition, which all falconers should be aware of.

Excessive casting :- young birds (under 12 days of age), in particular merlin chicks (up to 20 days of age), are particularly poor at producing a casting. No casting should be offered to chicks until they are over 12 days, even then casting should be minimal, and preferably of a soft nature. Fur (eg. rat / mouse / rabbit), is particularly difficult


for them to deal with, whilst chick down is considerably easier. If you are feeding fur to young, always check for castings, and if not present a swollen anterior abdomen (just below the back edge of the keel) is often apparent.

Many breeders try to improve the dietary quality of their birds immediately prior to breeding. This may involve the feeding of more rat or mouse. Immediately prior to egg laying, the female bird has a significantly reduced amount of space in the abdomen. This arises as the oviduct has increased in size to approximately thirty times it's non breeding size. At the same time follicles are developing on the ovary. There may be several follicles present each being several centimetres in diameter. The consequence is that there is less room for a casting to be expelled.We have had one case of a bird, in this situation which was being fed on a rat diet. The bird was totally unable to cast, as their was insufficient room for the casting to move back up from the stomach, passed the ovary and portions of the oviduct to the crop. The bird was found collapsed and dead on the nest (so near and yet so far), the cause was only revealed on post mortem. The moral is not to give excessive casting to birds immediately prior to egg laying.

Feeding on top of a casting :- one would hope that all falconers are aware that a bird should not be fed until after it has cast. If a casting is comprised only of 'chick down' the bird will normally cope with it, but feeding on top of a fur casting can lead to disaster. If the casting passes into the small intestine it is likely to cause an obstruction. Such a bird will pass either very small, dry and dark mutes, or mutes with no coloured segment at all. The bird will be inappetant and may regurgitate. Experienced veterinary care is urgently required.

Inadvertent ingestion of indigestible matter :- chicks reared on peat, and older birds fed on wood shavings may ingest peat or wood shavings respectively with their food. Birds are rarely able to cast such materials, which rapidly build up in the stomach, forming a complete obstruction. The falconer should be aware that the bird's condition may be declining, whilst it's weight remains constant. Assessing the birds condition by reference to it's weight alone can be dangerously misleading. Urgent specialised veterinary assistance is required, surgery is generally indicated.Some birds are darn right daft when it comes to eating silly things. In the case of Harris' hawks, they are certainly very intelligent compared with other popular falconry birds. On occasions even the best made falconer's knot, can be undone by a Harris' hawk. Usually that is the end of the matter, so long as the bird doesn't fly off. We have a couple of occasions when having undone the leash, the bird seems to have suddenly found it's true vocation. They have then proceeded to remove the leash from the swivel, and promptly swallow the entire length of the leash, in true 'Secretary Bird' style. As long as the bird is discovered whilst the leash is still in the crop, most owners will realise what has actually happened. Surgical removal under anaesthetic is generally straight forward, either via the mouth, or through the crop wall.Owls are a law unto themselves when it comes to eating twigs. Both owls in captivity and in the wild, on occasion eat very long twigs (sometimes 6 - 8 inches long). The bird will appear inappetant, uncomfortable and miserable. If one is lucky the bird will bring the twig back, but on other occasions it may cause a gut perforation, leading to the bird's death before the keeper or the vet is aware what is wrong. Another form of obstruction that we have seen especially in the larger owls is the ingestion of pea gravel. One sees is a bird which is very thin, but whose weight is remarkably high. The stomach is full of gravel, there is less room to accommodate food, hunger is not as apparent as the stomach feels stretched already, but the bird is loosing condition very fast. These cases seem often not to diagnosed until the condition is very severe, in part because of the large size and thick feathering of the eagle owls, obscures the weight loss.. If the bird is not handled, they are unaware of the severity of the situation until it is almost to late.

Ingestion of over size food items :- the ingestion of over size bony items of food can on occasions be disastrous. Rabbit femurs (thigh bones), may be too long to immediately pass on into the stomach. Given time these are usually digested and pass on down, however on occasions they can cause the bird great discomfort, sometimes leading to damage of the oesophageal lining. Recently a keeper who has fed his bird pheasant necks, when in season, for a long time, presented his bird, in great discomfort. The bird was coughing blood from it's wind pipe (trachea). Radiography confirmed that a section of pheasant neck was indeed stuck, (in a manner similar to Winnie the Pooh in rabbit's hole), in the distal oesophagus, ie. below the crop, but not yet into the stomach. The pheasant neck rather than going straight down, had doubled over. In this doubled up state it was too large to pass on. In this position it was pressing hard on the lung tissue, (in the chest), which was causing the bleeding into the wind pipe. Surgery was performed. The gut was entered via the crop wall, from where the bone could be carefully grasped and gently removed. The pheasant neck had been lodged in this position for some 18 hours and was starting to putrefy, together with additional food which had been given on top of the pheasant neck. I am glad to report that the bird made an uneventful and full recovery.

A prickly tale:- our most unusual and most recent obstruction, which has prompted me to write this article. A female red tail, whilst sitting quietly on its bow one evening, was surprised to see a hedgehog taking a short cut across the weathering lawn. Never one to miss an opportunity, the hedgehog was quickly grasped, dispatched and ingested. I imagine it wasn't until some hours later, that she began to regret the fact that her greed had got the better of her. The birds owner phoned some 18 hours later when no casting had appeared. The bird herself looked larger than life, and as fit as a fiddle, but a barium meal radiograph confirmed that she did have a very large belly full of totally indigestible hedgehog fur and spines. Surgery was performed, with the stomach being opened via the abdomen. Surgery was uncomplicated and the birds recovery was uneventful..


To conclude falconers should appreciate that whilst some upper gut obstructions, are totally unpredictable and unpreventable, others can with knowledge and fore sight be avoided.

Water:- as previously stated, although raptors under normal daily conditions usually do not drink, when ill, stressed, in hot weather etc. they will often need to drink. With this in mind water should be available for birds on a daily basis. Care should be taken in choosing a suitable water vessel as birds are able to drown themselves in even the shallowest container.

Hawks, Hygiene and Eating:- As previous stated the hygiene of the food supply, during it's preparation, and the way and manner in which it is given is very important. However many falconers are blasé about their own hygiene when in the presence of their bird. We must accept that infections such as Salmonella enteridis are rife in the poultry industry, and hence will also be in day old chicks. Likewise avian tuberculosis is common in feral birds. Either infection can be a serious pathogen to ourselves, so care should be taken. We are all prone, when short of a hand, to pull a gauntlet off with our teeth, temporarily forgetting who just got eaten on the fist, or who muted on it. Furthermore knives used in food preparation, as well as the occasional footing of your hand by your bird can introduce tetanus, which we all know is a dangerous and potentially fatal disease. Needless to say all falconers must have an up to date tetanus injection. Consult your own GP, most advise a booster every ten years.

Calcium Deficiency in Adult Birds:-As previously mentioned a diet should be varied and mixed, comprising of whole carcasses. However for display birds who are flying daily in front of the public and are 'fed up' afterwards, whilst the spectators questions are being answered, this can be a problem. Understandably the public find a lump of meat far more acceptable than a fluffy chick or a rat. In this situation it is best to give just half a crop then feed up on rat etc later. If meat is fed for any significant part of the daily food intake, they must also offset this deficiency by adding a calcium supplement such as 'Nutrobal' (Vetark)

Emergencies how to deal with each:-Damage to Surface of the Head

Damage to these areas will arise in a number of situations, firstly we will consider the aviary bird.

Many birds cause damage to themselves when startled or upset in the aviary, scalping the top of the head, or cere on the roof of the aviary. Firstly this should be minimised by designing the aviary such that they are not startled by passers by. Secondly when you have to go in to catch birds, use a large necked, light weight, (extending if necessary) fisherman's landing net. This is far quicker and more efficient than catching by hand. Furthermore as the bird is caught its reaction is to clench it's talons. If this is done into the net, the bird holds itself tight against the net, whilst if caught by hand, he either foots you, or worse still himself, which may well lead to bumblefoot. Thirdly the roof of the aviary should be lined with some soft material which will prevent damage, this is especially important in flighty birds such as goshawks.

The material used for lining or creating the roof and sides of an aviary may allow the bird to see out, however they should be of a sufficiently dense nature that the bird does not crash into it, but sees it and turns before hitting it. In this way many injuries to young or recently captive birds can be prevented. Such materials used for lining aviaries and stopping self trauma need not be strong, as it is only a covering and acts by highlighting to the bird that their is a barrier, so more often the bird will swerve and turn before hitting the fence. The best prevention is the placement of parallel batons or rods 3.5 - 4" apart up the sides and roof of the aviary.

Treatment:- if damage is slight, then one should just check that it is clean, not bleeding copiously, and perhaps apply some antibiotic wound powder. One should take care in using wound powders on birds. Several wound powders both human and veterinary, which are routinely used on all other species, are in fact toxic to birds. This occurs as wound powders do on occasion contain a local anaesthetic agent, in order to reduce the pain of a graze or wound. Birds are very sensitive to these compounds, and can die rapidly.

Before use, check that the preparation does not contain any constituent with affix 'aine' on it e.g. BENZOCAINE.

If the bird has scalped itself then check to see how large the resultant skin deficit is. If the hole is in excess of 0.75 cm then the bird will require veterinary treatment.

Such treatment is likely to involve a quick anaesthetic and a suture or two. Care should always be taken in doing this as if the skin edges are pulled together, following an area of skin loss, this can result in upward distortion of the eyelids, this in itself can lead to further complications. In these situations, what is termed a 'pedicle skin graft' can be used. This involves the movement of a piece of skin, including it's blood supply from an area lower on the neck. Care is required in order to ensure that the final direction of feather growth, is normal. If this is not done the result can be a Mohican goshawk.

Damage to the Beak

On occasions birds will have t6he entire upper beak removed by another bird. This situation usually arises where Harris Hawks are in adjacent aviaries. In particular where wood panelling is used to separate the two. Panelling will often include small knots (eyes) in the wood. These are fine when the aviary is built, but with the passage of time, and the effect of weather, such knots fall out. Harris Hawks, being the inquisitive birds that they


are, believe that it is essential that they peer through the resultant hole. On the other side, the fellow bird believes it is equally important to remove any beak, eye, foot that it can possibly get hold of.

Treatment: if only the tip of the beak is damaged, then it should be coped back, as far as is necessary in order to prevent further cracking. If the growth area of the beak itself is damaged (i.e.. the area just below the nares where the beak grows from), then there may well be permanent impairment of beak growth, even to the extent that a top beak may never grow again. In this situation one is often asked if one can put on a replacement. The answer to this is that if only a temporary artificial beak is required whilst the original grows back down, this is possible.

However it is not currently possible to place a permanent false beak, as the sites of anchorage in the bone of the upper beak will eventually give way, so it will not be an adequate long-term solution.

In the event of cracks, or tears in the beak, as stated previously these should be cut out. If the crack goes so far that this is impossible, then some form of support is necessary over the crack, whilst it grows out, so that it grows down, as opposed to continuing upwards. Such a procedure should usually be carried out by a vet as it may involve placing wires through the beak, which must be carried out under anaesthetic.

Occasionally the bones of the lower beak may become fractured, these can be relatively easily repaired by a veterinary surgeon, by placing a pin down each bone. Such a technique will be affected by any degree of bone loss which may have occurred, as well as the size of the bones in the affected species.

If on any occasion a bird is seen to be unable to pull at food, or close it's mouth it must be caught up immediately and closely examined.

Other common ailments which may lead to similar signs affecting the mouth are 'frounce' (infection by trichomoniasis), capillariasis (infection by the parasitic worm capillaria, or candida (yeast) infection. Occasionally a mild form of pox virus (commonly pigeon pox) can lead to similar signs. It is important that one differentiates between these three organisms, as the treatment is different, and specific for each ailment.

Damage to Eyes

30% of all wild trauma cases have haemorrhage in the posterior chamber of the eye. In mammals retinal function (i.e.. the ability to see) is easily tested by examining an animal in a dark room and shining a bright light at the pupil (dark centre to the eye). In birds such tests are however not so reliable, as birds also posses voluntary control over the muscles of the iris. In view of this, normal function is tested by trying to elicit a menace response. In other words you move a finger or object close to each eye in turn, and see if the bird makes any evasive reaction. In doing this one should be certain that the bird is not reacting to movement of air as opposed to visual movement. When damage to an eye is suspected, the bird must be examined very carefully, and if any doubt exists, it should be immediately referred to a vet. Eyes are delicate and vital structures and hence no risks should be taken or assumptions made. All eye injuries must be examined by an experienced vet as soon as possible.

It is often tempting to use some eye preparation which was previously dispensed for another eye condition. Such temptation should be avoided, as serious damage can ensue. This is particularly important when there is corneal damage. If an ocular preparation is applied which contains steroid (a common constituent of some eye preparations) the corneal damage is likely to become considerably worse rather than improving.

Birds eyes are much larger than those of other species, in view of this a deep puncture in the top of the head, may in fact puncture the eye globe even when the wound is a considerable distance from the eyelids, hence any wound about the head should be considered serious.

Puncture of the cornea (front of the eye) is not uncommon, particularly in hunting goshawks, frequently caused by gorse or blackthorn spikes entering the orbit.

Birds have three eyelids, the top and bottom, which open and close normally. As well as these they also have a third eyelid, which acts somewhat as a visor, it crosses the eye from the direction of the nostril, in order to protect the cornea (surface of the eye). As a result of the action of the third eyelid, the incidence of corneal damage is reduced. On some occasions when a thorn does penetrate, the latter may enter through the third eyelid, straight into the eyeball, at the same time pinning the third eyelid in place over the eye. This situation is predictably extremely painful, and if left to its own devices the bird will try to brush the offending thorn out. If one is faced with this situation, and if one has adequate assistance, then the bird should be very carefully and firmly restrained on it's side, the pair of forceps in the first aid kit may then be used to grasp the end of the thorn and pull it firmly straight out in an exact reverse direction from which it entered. Every care should be taken to avoid breaking the thorn off in the eye. This procedure should only be attempted if the thorn is causing great discomfort, and is protruding clearly from the eyeball.

It is then of great importance the bird is examined as soon as humanly possible by an experienced veterinary surgeon. A delay of more then six hours from the time of injury can lead to the loss of the eye, and disfigurement of the bird. The treatment given by the vet will need to be extremely comprehensive, in order that infection, inflammation and the corneal puncture can be controlled. See the rehabilitation section for the assessment of vision prior to releases.


Conditions Affecting the Wings

Damage to wings is perhaps one of the commonest injuries to both falconer's and wild raptors. Injuries occur whilst in an aviary, tethered on a perch and whilst being flown. Frequently the first sign is a

bird who is hanging a wing. This sign alone should ring warning bells in the mind of all bird keepers. The angle at which the wing is hanging and the way in which it is actually held will often indicate the area of the wing which is damaged.

Occasionally the injury may have arisen as a result of a simple strain, to soft tissues, and as such will return to normal within a short period. However in the many cases the damage is more severe. In all these cases the bird must be presented to a veterinary surgeon, in order that x-rays, and possibly other tests can be carried out. If for any reason there is going to be some delay between finding the injury and being able to seek veterinary attention then the wing may be strapped against the body in a normal physiological position. This should only be attempted in the unlikely event of a delay, as the restraint and handling that is necessary, will cause pain and fright which will worsen any clinical shock that the bird may be suffering from.

The temporary stabilisation of the injured wing against the body can be achieved by placing the whole bird in an elasticated tube, a sock, stocking or 'Tubigrip Dressing' of suitable size may be used. This should not be excessively tight across the birds chest, as this could adversely affect any respiratory difficulties. Having placed the bird inside this, the head and top of the neck is exteriorised, equally holes in appropriate positions can be made for undamaged wings, legs, as well as a suitable hole for the passage of faeces. Alternatively the same effect can be achieved by applying strips of 'Vetrap' (3Ms), 'Colastic' (Millpledge) or strips of label paper (with water soluble glue) over the leading edge of the affected wing, as well as between the tips of the primaries. A further method using a figure of eight strapping around the injured wing itself is illustrated below, an improved version of this, and one which you can easily prepare yourself is the use of a canvas or leather Braille, as shown below.

Shown below is a list of some of the possible injuries which can befall a birds wing, without radiology an accurate diagnosis can usually not be made, hence the need for a rapid trip to your vet.

Fractures of:-Coracoid/Furcula/Scapula (shoulder attachment)

HumerusUlna and or radiusCarpal and

metacarpal bonesAllula

Dislocations of:- ShoulderElbowWrist (carpal joint)

Soft tissue injuries to:- All muscles and tendons of arm & shoulder, including

the propatagium (the band of skin which forms the leading edge of the wing and is a very sensitive

structure which is easily damaged).

Infection of: Clavicular air sac, all joints, muscles and tendons of wing.

Loss of blood supply: MycotoxicosisWingtip oedema &

dry gangrene syndromeImpairment of

blood supply following previous trauma.

Principals of Avian Bone RepairFractured bird bones heal very rapidly compared to

mammals. This is of special significance in the casualty wild bird as the bird may well have fractured the bone several days, a week or more before it has ever been picked up. Although such birds must be nursed through the initial shock period before any attempt is made at repair, recuperation must not be left too long, otherwise the bones may well heal of their own accord in quite the wrong position. Subsequent re-fracture and


realignment is more complicated, expensive long winded, and carries an increased risk of an unacceptable final result.

More over any fracture which occurs close to a joint (as well as dislocations) should be considered to have a grave prognosis, as such fractures often lead to reduced joint function. In these cases it is important that the fracture is stabilised immediately and the wing should preferably not be strapped up for more than 4 - 5 days. It is important that normal joint function is restored as quickly as possible and movement encouraged in a hope of preventing ankylosis (stiffening) of the joint (see later for physiotherapy).

Analysis of Avian Fractures, their repair & prognosis

The first decision to be made is how good has the final result got to be, in other words what function has that bird in the future. Whether one is dealing with a wild injured bird, or a falconer's bird the aim must of course be for full normal perfect flight, ability to catch prey and to have normal weight bearing on each foot such that bumblefoot does not develop as a consequence of excessive weight bearing on either foot. An aviary bird does not perhaps have to be so good, although one must always strive towards perfection. Even for an aviary bird, perfection may be a prerequisite for survival, for example a male goshawk which is a little slow around the aviary is likely to rapidly become a dead goshawk. Having concluded that perfection is required, next one must consider if there is any chance of achieving it. As will be seen by the analysis of cases below, certain fracture situations will always lead to disaster, even in the hands of the best international raptor orthopaedic surgeons. Such cases must therefore be considered carefully. It is the authors view that the single goal of treating injured wild birds should be to release them back to the wild in perfect condition. It is appreciated that some permanent casualties can be of value in rearing orphan young, in order to prevent the inevitable imprinting that would otherwise occur. However for the vast majority of cases, if disaster is certain, then rather than expending valuable resources, occupying much needed aviary space and committing a permanent invalid to confinement then euthanasia should be the treatment of choice.Before fracture repair is contemplated, one must first ensure that no other injuries, diseases or infections are of greater life threatening importance. When a bird has suffered sufficient trauma to fracture a bone there may well also be other internal injuries present.The factors which govern fracture repair include :-

Which bone is fracturedThe type of fractureThe condition of the fracture & surrounding tissueThe method of fracture repair

All figures referring to success rates are extracted from 'Analysis of Avian Fracture Repairs: Implications for Captive & Wild Birds'. The paper was presented at the 1993 AAV Congress by Drs Howard & Redig from the Raptor Centre, Minnesota. The latter centre is the largest and busiest in USA, which handle 250-300 avian fracture cases annually. Figures refer to cases presented from 1990-92 (24 month period).

Admissions 802Birds with fractures 542Fracture Incidents 549No fractured long bones 733Incidents with 1 fracture 398

2 21 3 27 4 3

The majority of birds suffered only 1 fracture, of those with two, 72% had unilateral (i.e. affecting one side of the body only) fractures of both the radius and ulna. Hence 88% of all cases had one or more fractures as a consequence of a single point trauma incident.

The condition of the fracture and the surrounding soft tissue at the time of admission were the most significant factors in the decision as to whether the bird received treatment or was euthanased. It is significant to note that 24% of all fractures were deemed to be beyond realistic repair at the time of admission, and were euthanased. This is a salutary point, and if we are attempting to save more than 76% of fracture cases, we are probably trying too hard, and our actions are certainly not in the bird’s best interests.

Days afterAdmission

Euthanasia due tofracture

Euthanasia for other reasons

Died Spontaneously

0 24% 4% 23 29% 5% 97 31% 6% 11


14 32% 7% 12Total 40% 10% 15

Taking a look further down the treatment and recovery line one sees that 40% of all fracture cases were finally euthanased. Perhaps such figures are reassuring, as we realise we are not doing too badly in comparison with the best in the world. By 14 days of initial admission the majority of birds which are not going to make it have become apparent. The figures for spontaneous death, and euthanasia due to other reasons reinforces the point that if a bird has suffered severe enough trauma to break bones there is a fairly high chance that other disease was already present or were caused at the same time.

The fracture type is also of great significance :-Closed no breach of the skinOpen skin broken, hence inevitably infection will have enteredOblique Transverse fracture typically leaving two large segmentsComminuted Shattering of bone with many small fracturesYou will note that not only do closed fractures have a better chance of healing, but they do so quicker (by 7

days).

Fracture type Closed OpenNo Fract % Healed Days No Fract % Healed Days

Comminuted 73 51 30 125 27 36Oblique 46 70 32 22 27 36

Segmental 29 45 28 20 25 69Transverse 155 46 33 82 27 33Unknown 18 28 28 84 0 -

Total 321 49% 31 333 20% 38

The percentage of birds finally released is also greater for closed fractures 49% c/w 20%.However if the fracture does heal, then it will have just the same chance of release, i.e. the problem if it is open is of greater soft tissue damage & necrosis but particularly infection.

The bone itself which is fractured also has a great effect on the final outcome. The reasons for this may be associated with the degree of soft tissue damage which must have occurred in order for that bone to have become fractured, whether that bone is susceptible to necrosis, displacement of fractures which is likely to occur at that site, proximity to vulnerable nerve tissue, and the likely hood for fragment protrusion through the skin.

Bone No cases No treated % treated healed % treated released

Days

Humerus 206 81 47 32 34Ulna 192 128 59 42 37Radius 133 64 64 30 28Metacarpal 72 39 62 51 31Corocoid 28 21 81 71 29Femur 27 15 60 40 31Tibiotarsus 51 26 65 42 30Tarsometatarsus 22 10 30 20 25

Treatment of the radius is linked to the treatment of the ulna in all but 15% of cases, as the ulna was also fractured. Fractures of the humerus are often open (59%), associated with devitalised bone & infection. The eventual release rates gives an indication of the chances for any bird with any given fracture. From the experiences of those at the raptor rehabilitation centre, it is clear that the minimum invasive surgery that has to be done in order to achieve the return of normal anatomical structure the better. The less that had to be done the better the recovery, in some senses this seems obvious, as the less that needs doing the more likely one is to have a good outcome. The following recommendations are made :-

1. Fractures with exposed devascularised necrotic or infected bone are unlikely to ever heal with normal anatomy and function. For wild injured birds with such fractures euthanasia is the treatment of choice.

2. Contaminated fractures (i.e. open but not obviously infected, i.e. usually <8hrs post trauma), should be cleaned as thoroughly as possible, the bones should be approximately opposed and immobilised, until such time as one can be certain that one has clean sterile vital tissue, at which point closer apposition may be indicated.

3. Highly comminuted fractures respond best to minimal surgical interference. Bandage or splint in good apposition, (possibly using small fine pins inserted without making a surgical incision.


4. Fractures of the humerus & femur always require rigid fixation because of the muscular forces surrounding them.

One other factor which will have a great bearing on eventual recovery rates, is the proximity of a fracture to a joint, or a dislocation in it's own right. The prognosis for a full return to normal flight in all such cases is grave, but is greatly improved by a minimal or zero period of joint immobilisation followed by a through course of physiotherapy.

PhysiotherapyPhysical fitness is the key to successful efficient and productive flight by raptors. The rehabilitation of an injured raptor is generally a lengthy process requiring precise diagnosis, medical stabilisation, prevention of inappropriate tissue repair and encouragement of rapid return to normal function.The vast majority of injuries raptors sustain while being flown are to their limbs. It isn't unusual for raptors being flown at rabbits or any quarry significantly larger than the birds themselves, to sustain significant traumatic injuries to their legs. Raptors following quarry into cover will also often damage their carpus (wrists). The importance of making a precise diagnosis cannot be emphasised strongly enough in these cases. Fractures close to joints are generally associated with ruptured ligaments, torn tendons and damaged joint cartilage and capsules, which destabilised that joint. Even if the fracture is healed unless the joint is stabilised, degeneration of the joint ensues and the raptor never regains full functional use of the wing again. Such a bird can never be expected to hunt again. When examining an injured raptor, a veterinary surgeon has several tissues he must individually assess. Having convinced himself that there is no irreversible nerve damage (eg fractured back/spinal cord or where a goshawk has been bucked and kicked by a rabbit) he concentrates on damaged skin, musculature, ligaments, tendons and bones. Initial treatment following thorough examination generally involves the disinfection of wounds followed by medical stabilisation (dressings, bandages), or if surgery is indicated immobilisation and sutures. In both cases adjunctive drug therapy will be required. Recovery and the requirement for physiotherapy will depend on the nature and extent of the initial injuries. The diagnosis and prognostic indications associated with the injuries should be determined by the examining vet, however an overview is shown in Table A. The condition being treated and rate of recovery will determine the specific exercise techniques required. In general, passive range-of-motion (PROM) is achieved by hospitalising the bird in a small cage (eg tea chest) which will enable the bird to stretch and extend its legs and wings but no more. This type of therapy is generally offered to birds during the initial phase of therapy and is often continued for three weeks, such confinement may only be legally carried out under the direction of a veterinary surgeon (see legal section). Active assisted range-of-motion (AAROM) is utilised when mobility of the joints has been reduced. Often this has to be performed by a veterinary surgeon with the bird anaesthetised, in order to stretch and loosen any contracted muscles, or break down pathological adhesions or scars. It may be prudent to hospitalise the bird for a fortnight and combine laser therapy with the physiotherapy to improve joint mobility. Active range of motion (AROM) exercise is generally the final stage of therapy. The therapist assists the bird’s wing spread by smoothly raising and lowering the gauntlet or gently rocking the gauntlet to encourage the bird to grip with its legs and extend and withdraw its wings. After a week the therapy progresses to allowing the bird unrestricted flight. Flying the bird to the gauntlet, on a creance if necessary, will be the final therapy required, to strengthen muscles and return suppleness to joints. If the injury is to one of the legs the muscles can be strengthened by offering tirings.

Table AType of Injury Goal of Corrective surgery/therapy Physical Therapy Program

1. Bruised muscleSprained ligaments

Rest to encourage resolution of tissue inflammation

PROM for 1 wk followed byAROM for 2 weeks

2. Joints (torn ligaments, joint capsule, cartilage)

Prevent loss of tissue flexibilityEncourage re-stabilisation of connective support of ligaments & jointsImmobilisation of joint for 5-15d, bandages, external fixator, pins

Involved joints are by necessity immobilised often -> decreased flexibility once materials are removed.PROM for all other jointsAAROM after materials removed for 2 weeksAROM for one month

3. Fractured wing/leg

Prevent loss of soft tissue flexibilityenhance muscle enduranceext/int fixators, preferably that do not stop joint movement

PROM until materials removedAROM for 2w after removal


Behavioural and physical acceptance of physical therapy is crucial before progression in treatment can be attempted. If this is not gained the excessive stress will only result in the bird re-traumatising itself. Modulation of therapy can be achieved by gradually varying the three parameters that describe exercise; frequency, duration and intensity. Frequency describes how often the raptor is exercised. One to three sessions of moderate exercise daily is usually appropriate. Duration describes how long the bird is exercised for, and is generally between 5 - 20 minutes. Intensity describes the effort of work required of the bird. Exercise progression is achieved by following one or two simple guide lines:

1. One parameter should be varied at a time (frequency, duration or intensity)2. Keep frequency to once or twice daily initially, then progress to three times daily. However, as duration and intensity of work increases towards the end of therapy (eg flight) drop the frequency back to once a day.3. Increase the intensity as tolerated by the bird once the duration of therapy has been increased to 20 minutes. Obviously reduce the duration of exercise when increasing the exercise intensity.4. Don't increase the exercise intensity if the patient cannot repeatedly perform the exercise exactly or comfortably.5. Constantly re-assess the quality of joint movement. Don't assume that the bird will tolerate the same exercise it performed the previous day.6. Generally if a bird can perform 15-20 repetitions each time it is exercised and it is exercised twice a day, then a new demand can be made.7. When ready the bird can be kept in an environment which encourages independent active movement and natural skills (eg mews). Of paramount importance is a precise definitive diagnosis by the veterinary surgeon and a strong sensitivity on the falconers part to the bird's behavioural and physical responses. One can appreciate the desire to fly a particularly good hawk at quarry as often as possible, especially if the season is drawing to an end, but inappropriate rest and treatment, for what might appear to you to have been an "insignificant knock" could well effect your hawk's ability to hunt for the rest of its life.

External Fixation

This is the original form of fracture repair, which relied on the two fracture ends being held stable, and correctly opposed in relation to each other. This method is only effective if the joint above and the joint below the bone in which the fracture is cited, can be immobilised. In view of this the technique is only of value in mid-shaft fractures, affecting the ulna, radius, tibio-tarsus, tarsometatarsus and very occasionally the humerus. This is so because it is impossible to immobilise the hip joint and not easy to immobilise the shoulder joint.

Furthermore as stated above it is important, especially if there is damage near a joint, that the joint is not kept static for too long. It is for these reasons that some form of internal or external pinning is now far more commonly used.

The exception to this rule is cases where the bone ends have pierced the skin, and infection has entered the fracture. In such cases although internal fixation may well be useful to immobilise the fracture, as infection is present no internal device should be used, as it will almost certainly be rejected, the bone infection will become more severe and either the bird will die or will require euthanasia.

A compromise can sometimes be achieved in such cases. If the bone is immobilised initially with some form of external support, in the meantime infection is controlled. Then if after a few days the bones are not starting to heal, and the infection has then been controlled, then internal fixation can be utilised. The latest development is the use of antibiotic impregnated bone cement, which may be implanted at the site of a bone infection. This bone cement will then slowly release antibiotic at that site for an extended period, often leading to a resolution of the infection.

Internal Fixation

This technique relies on a veterinary surgeon, anaesthetising and operating on a bird, and implanting a stainless steel or plastic (permanent or dissolving) rod or pin inside the bone, with or without bone cement or a series of transverse steel pins through the bone. Occasionally in very large birds a stainless steal plate and screws may be employed, however the cortex (outer wall) of birds bones is rarely strong enough to support such techniques.

In any case where the keeper suspects a fracture, or the wing is continually or intermittently drooped for more than twelve hours, the bird should be admitted to a veterinary surgeon for examination and x-rays.

DislocationsThese may affect any of the joints of the wing, they may comprise a straight forward dislocation, or a minor

fracture may be present in the joint as well. Radiographs are essential, in order to differentiate. Dislocations stand the best possible chance of success if treated and reduced immediately. Generally shoulder dislocations are the easiest to deal with, as the joint has considerable muscular support following replacement. Elbow and wrist (carpus) dislocations hold a poorer prognosis, but the quicker the treatment, the better the prognosis. If a dislocation is 'compound' i.e. open to the outside and infected, the prognosis is hopeless.


Damage to Primary FeathersA frequent cause for concern by falconers is the lost or damage to flight primary wing or deck feathers.

When a feather initially develops, it grows from the centre of the feather follicle, from the dermal papilla, running up the centre of the developing feather is the 'central axial artery and vein'. At this stage of development the feather is describes in lay terms as being "in the blood".

The feather grows from one specific area in the feather pulp named the 'dermal papilla' see diagram opposite. The feather is held in place by the epidermal collar, and the epidermal sheath which proliferates from it, to form the feather sheath.

If a feather which is still developing (in the blood) is removed, the dermal papilla, and epidermal collar will be damaged. Furthermore as the area is very vascular at this stage bleeding will occur into the empty feather follicle. If the plucked feather is young the epidermal lining may be plucked away before it breaks off from the feather, if this occurs the feather may not regrow at all, ever. The reason for this is that with the removal or damage to the epidermal lining, the dermis on either side heals against each other, therefore eliminating the feather follicle.

If the feather is old or mature, the epidermis is tougher, and is relatively stronger in comparison with the junction between the feather and the dermal plug. This being so, if the feather is plucked out then the epidermis is unlikely to be damaged, and hence the feather is likely to regrow either immediately, or occasionally waiting until the next moult.

From this we can conclude that every effort must be made to prevent damage to feathers which are in the blood. If a mature feather is broken it is best left to be replaced at the next moult. If a mature feather is removed, it was previously thought necessary to plug the feather follicle open, lest it should become blocked and prevent the new feather growing down. If a new feather wants to grow down, it will find a way out. If a feather which is in the blood is broken off, any bleeding may be stemmed by pushing a small rolled length of haemostatic swab down the feather quill. If possible the feather shaft should be left in place at least until the stub is mature and is no longer in the blood. If it is then removed there is less chance of damaging the vital dermal papilla, which might lead to a failure to re-grow.

If a bird is found to be pulling it's feathers out, the first course of treatment should be the application of an effective ecto-parasitic preparation (see parasitology later). If no improvement is immediately apparent then veterinary advise should be sought. There is often a bacterial infection in the feather follicle which is leading to irritation, causing the bird to mutilate itself. Other causes are ineffective parasitic treatment (incorrect drug, or the presence of a mite within the feather), psychological problems, feather or preen gland defects.

FEATHER AND BEAK.Wild or trained hawks need near perfect plumage to be efficient in the field and a bird with damaged or beat up plumage can not be expected to survive in the wild. Certainly the incidence of fractured feathers is far higher in captive birds than in wild ones. The main

reason for this occurrence is the poor tolerance of inappropriate aviary design by the raptor, or an unsettled bird being tethered to a block. Birds kept in aviaries, made with mesh or screen material which appears transparent results in the bird flying full tilt into the sides of the aviary damaging their feathers. Birds are also prone to feather breakage if their plumage shows signs of stress or fret marks. These weakness are caused by any physiological stress the bird might have been exposed to (a wild bird suddenly finding itself in captivity, nutritional stress) during the moult. In all cases, broken feathers should be fixed at once. As a basic rule finger-tip fractures can be ignored but any feather loss greater than 2 inches needs immediate attention. The splicing of a broken feather is called 'imping' and is a relatively easy procedure. A feather of suitable length and shape is selected. Ideally the feather should be collected from a bird of the same sex and species to the one being impede. The technique is to cut the fractured feather-shaft off clean with a pair of sharp scissors or a knife. Care must be taken not to damage any of the adjacent web. Similarly the feather to be added is cut to an appropriate length. The two feathers are attached using a strong, flexible light material. The author prefers to use piano wire which is supple, so no loss of feather flexibility occurs, so the feather remains dynamic and responsive to turbulence created when a falcon stoops at its quarry. Other people recommend the use of bamboo splinters, carbon fibre etc. Which ever material you choose, ensure that you sand it down thin enough to ensure you do not slit the shaft of either feather when you insert the shuttle pin into the stem of either piece of feather. The pin should also be filled to retain a triangular shape to ensure that no rotation of the impede feathers occurs. Before placing the pin, it can be dipped into one of Page 22 Copyright Neil A Forbes FRCVS 1996

the new flexible bonding agents to help keep it in place When imping feathers it is often important to sacrifice a large section of normal shaft, so where only 2 inches of a feather tip have been lost, the shaft diameter will be too narrow to accept the thinnest pin without splitting the feather shafts. The handling of the bird while imping is sometimes a problem, but by casting the bird, restraining it in a towel or using a hood you will have very little difficulty with the procedure.Even just before or during the moult broken feathers should be repaired. The sequence of moult of long feathers is always such that, except for the outermost tail and wing feathers, the new feather always comes down between two of the older, full grown feathers. Any adjacent 'old' feather that is broken will not be able to support and shield the new and developing feather. Should the new feather be broken while soft, 'in the blood ', the entire moult will be ruined through the neglect of one long feather.Before going onto the moult-sequence itself and some of the modern techniques of moulting hawks, it should be stated that many raptor keepers worry far to much about the moult . There is considerable evidence that a complete moult is not the norm among wild raptors. However, a complete moult is highly desirable in any hawk and should be encouraged. Younger birds consistently moult better than haggards.Wild breeding male raptors have the onset of moult delayed about thirty days beyond the females and non-breeding males and magnifies a very complicated and sensitive endocrine (hormones) system. Captive bred birds have little difficulty adjusting to a life of domesticity, but wild hawks kept as patients are exposed to dramatic stress levels, which appears to be sufficient to induce maladjustment to the endocrine system. It follows therefore, that birds should be kept healthy, in a stress free environment, fed ad libitum good quality food and as long as no long feathers are damaged during the moult the birds released as soon as possible. Nutritional supplements should be given whilst the bird is moulting.Drugs are available from veterinary surgeons to help encourage the moult, but OLD DRUGS USED TO TREAT THIS CONDITION MAY BE EXTREMELY TOXIC IF USED AT INAPPROPRIATE DOSES. Traditionally thyroid hormone has been used, however often it did not work, and the therapeutic dose was extremely close to the toxic dose. Sex hormone drugs are far safer, new work is progressing in this field, as yet it is not known which hormones will work best in raptors, however it is considered that their use in raptors is rarely justified.Besides paying careful attention to preserve our raptors flight feathers and plumage we must not neglect to care for their beaks and talons. The 'soft' environment of an aviary result in talons becoming overgrown, where in the wild more natural perching surfaces would abrade the keratin and keep the talons at an appropriate length. Similarly the common diet of ‘day old chicks are 'soft' and offers little resistance against the beak or neck and leg muscles. The effect on the beak is more noticeable than the muscles, with the upper mandible becoming over grown and cracked. These cracks are more evident in falcons where they migrate from the 'tooth' up the beak towards the nares. These cracks must not be ignored, besides being painful, they are extremely difficult to correct if they have been left to migrate well up the beak. In these cases veterinary assistance will be required for the placement of a tension band wire across the crack or the use of specialised corrective trimming. Birds kept in captivity for any period longer than a month should be offered food that is more 'tendon on bone' than 'flesh on breast' at least once a day each week. This food, called tiring by falconers, will help 'trim' the beak. Inspite of this it might still be necessary to occasionally catch the hawk and file its talons and beak. This procedure is referred to as 'coping the beak and talons' in some texts. In cases of poor beak or talon growth or strength, then the B Vitamin 'Biotin' may be used daily in tablet form to increase to quality and rate of beak growth.

Wingtip Oedema and Dry Gangrene of Birds

This condition has been recognised for some years, but has been seen much more frequently since 1988. The condition is most commonly seen in Harris Hawks, Peregrines, Lanner & Lugger Falcons. It has also been seen in eagle owls, hobbys, black kites, tawny eagle and others. It usually occurs between October and April of any year, and is only seen in birds which have been exposed to cold weather. Any affected birds are likely to have been within 18 inches of the ground at the time of the cold weather. The first signs are a bird which is slightly fluffed up, holding one or both wings slightly away from the body. If the tips of the wings are examined, there will be found to be extreme swelling (often 2-3x as thick as normal) of the wing tip. The swelling commences at the tip of the wing, the more severe the incidence the further up the wing the swelling extends.

Often the signs are not seen until several days after the initial insult. This can lead to confusion as the prevailing weather conditions at the time of onset. The weather may have appeared to be mild, however it may have started a few days (having not been immediately noticed) earlier when the weather was cold.

Treatment :- this consists of warming the bird up, rubbing vascular stimulants (such as Preparation H or Granugel) into the wing tip and encouraging the bird to use the wing in an attempt to encourage blood supply. Laser therapy and circulatory stimulants such as the drug 'Vivotonin' (Hoescht Animal Health) or Isoxoprine (Navilox. Univet. 5-10mg/kg daily) may also be useful. Currently the best success rates are being achieved with a combination of Navilox and glucocorticosteroid with covering broad spectrum antibiotics. The disease course spans some 6-8 weeks. Often all appears to be doing well, then the skin on the tip appears to become darker and hard. Once this starts there is no hope of a full recovery. The wing tip including the bottom 5-6 primaries drop off never to be replaced.

Prevention :- the full cause of Wing Tip Oedema and Dry Gangrene is not fully understood, however exposure to ground frosts is a prerequisite.


Birds which are loose in an aviary and those which are kept in an indoor mews, are generally not affected. One confusing aspect is that the clinical signs, especially in mild cases may not be evident until several days after the precipitating insult. Very often the peak incidence is not in the middle of the winter when falconers expect cold weather, but in the autumn or spring when they can be caught out by the odd uncharacteristic cold night. Often the frost on such nights, is not present when the owner goes to bed, and has gone by the morning, however the damage has been done in the interim.

On some occasions the initial damage will go undetected, so the first sign is when the wing tips actually fall off. This needless to say can be an alarming experience, particularly if one is not expecting it.

A similar condition can arise following previous trauma to the upper wing, it is presumed that this arises as a response to impaired blood supply to the wing tip.

'Blaine' or Carpal Bursitis

This condition affects the wrist joint of the bird, i.e. the forward facing joint, from behind which the primaries extend. The bird may be seen to be hanging a wing, a swelling is evident around the joint. The condition arises following a traumatic injury, either a knock whilst out flying, or a brushing wound when bating off a perch. The injury affects the tendon sheath as it runs over the joint.

Treatment :- the most important aim is to avoid infection. If the latter occurs the future functioning of the wing is likely to be impaired. Antibiotics and locally applied anti-inflammatory agents must be used.

Swollen JointsThese may occur for a number of reasons. As above they may arise following trauma, or as a consequence of a generalised infection affecting the whole body, which settles out in the joints. Salmonella typhimurium is the infection which most commonly causes swelling in several joints at any one time. Any bird showing a swelling on a joint should be seen by a vet, as the consequences of joint infections are serious and often permanent. As stated previously there are reasons for a bird drooping a wing other than trauma, however these may be just as important, and require treatment just as quickly. An example of this is aspergillus infection in a clavicular air sac which may lead to lameness in that wing. Diagnosis is made by ruling out other causes following radiographs, then blood sampling and endoscopy. If the treatment for aspergillosis is to be successful, then treatment must be instigated immediately.

Conditions Affecting the Legs, Feet, Talons

Perhaps the commonest emergency affecting the feet is the loss of a talon. This usually occurs as the result of a hunting accident, and will result in copious bleeding.

Included in the first aid kit is a pot containing potassium permanganate crystals, also a container of water. Add a small volume of water to the crystals, shake to dissolve, then dip the bleeding remnant of a talon in the solution. This should stop the bleeding quickly. Then dress the talon with a vasoactive dressing (eg. granuflex) to keep the nail bed moist and assist in stimulating regrowth. Regrowth typically takes 6 - 8 weeks.

In the fullness of time a new talon (sheath covering the sensitive inner quick) will usually grow, as long as the area from which it grows has not been excessively traumatised. However in the meantime the bird may not be flown at quarry, nor be allowed to hit a lure with any force, for fear of causing further trauma prior the formation of a protective covering to the talon.

If rather than loosing the outer sheath of a talon, a crack or other blemish appears in the talon, usually the necessary action is for the talon to be cut back above the blemish. This is best carried out under anaesthetic. In this situation antibiotics will often be required in order to prevent infection of the bed of the talon. The talon should then be dressed as above.

Fractured ToePage 24 Copyright Neil A Forbes FRCVS 1996

This is not an uncommon injury, but will often be difficult to differentiate from a severely bruised toe. Often the only method, of differentiation will be by taking a good quality x-ray.

Any severely swollen toe, should be seen by a vet immediately if it appears out of line, held at a peculiar angle, or if there seems to be in severe pain. If there is any breach of the skin the bird is also likely to require antibiotics. If you have a bird with a severely damaged foot and cannot reach a vet immediately then a 'ball bandage' should be applied to the foot. The ball bandage is also useful if one has a wild bird which has been in captivity for a considerable period and the talons have become over long. If the ball bandage is applied wet, and left on for 3-4 days, then removed any old redundant talon will be loose and easily removed, leaving a razor sharp fresh talon, ready for 'killing for a living' back in the wild. This technique should only be used immediately prior to rehabilitation.

A diagram of a ball bandage is shown below. It should be remembered that when applying a bandage to any extremity the tape should not be applied too tight, in particular if one is dressing a wound which might swell up further. If the dressing is too tight then the blood supply will be cut off, and gangrene will set in. Fractured toes should never be left immobilised for more than 7 days as this may lead to long-term reduced functional ability.

Bite Wounds to ToesThese will be dealt with in detail in a later section. The principle is that the toe should be washed

immediately using an antiseptic solution (see pevidine wash or F10 as supplied in first aid kit). One should always bare in mind the fact that teeth, (in particular cats) are usually infected, although the surface wound looks clean, often infection has been taken deep inside. The authors advise is that any severely bitten bird should always receive antibiotics. A slight bite in an accipiter or buteo can be treated by regular bathing in antiseptic and watching carefully for signs of swelling, heat or redness which might indicate infection. If such signs do develop the bird should be taken to a vet, for antibiotics to be prescribed. In contrast any falcon suffering any perforation or breach in the integrity of the skin should receive antibiosis. Any bite into or near a joint should be considered seriously.

Please note Medicines Act, it is illegal to supply antibiotics prescribed to you for your bird to anyone else for their bird.

In the case of injuries to the feet of falcons, however slight I believe that antibiotics should be used, as once infection enters, the treatment of bumblefoot is so much more serious. Pressure should also be taken off the injured area in particular if on the base of the foot. This is done by taping on a corn plaster or similar, in order to raise the affected area from the ground, so that it is not weight bearing.

Bumblefoot

This condition has plagued falconers for years. Bumblefoot is an inflammatory and usually infected reaction affecting any part of the foot. Typically the foot is infected with bacterial, yeast or fungal infections. The initial condition arises when the integrity of the skin of the foot is breached in some manner. There are a number of ways in which this may occur. Firstly the bird may have suffered a cut foot, thorn entering, abrasion on rough aviary netting or wire, pierced foot from the birds own talons, or simply a corn on the base of the foot which arises as a result of improper perching materials. The corn appears because too much weight is being born by one specific area of the foot. The condition bares many similarities to a bed sore. Even if the condition arises through one of the other means, the swelling of the foot, will cause weight bearing on inappropriate areas and hence secondary pressure sores. The pressure sore arises as although the foot has a good blood supply, whilst the bird is static on the foot, the pressure of the birds weight reduces the blood supply to the damaged area.

Prevention is achieved by keeping the perches and feet as clean as possible. It is however important that any disinfectant used on the perches is cleaned off well before the bird uses it again, as such disinfectants can be irritant in themselves. Healthy skin is maintained by periodically applying vascular stimulants such as 'Preparation H' (available from any chemist) to the feet. The aviary must be designed so that there are no sharp or rough structures that the bird may grasp. A number of different perch materials and surfaces should be provided, these will be chosen with respect to the size and weight of bird one is taking care of. Although the talons will need to be very sharp at the time of release to the wild, if there will be some delay before release the talons should always be kept coped , in particular the hind talon.

It is imperative that the blood supply to the birds feet is stimulated and that the birds weight is off the feet for as much of the time as possible. With this in mind it is advantageous that the bird is flown regularly, if this is not possible, at least ensure that the aviary is as large as possible. Birds should be prevented from bating onto concrete or other hard surfaces, and if the bird is flown to the lure, ensure that the bird does not hit the lure too hard, as this will only bruise the foot.

It is crucial that rehabilitation birds are examined regularly just as one would a falconers bird being flown daily. There really is little excuse for a bird to develop chronic bumblefoot, or it going unnoticed once it has arisen. Even if you are not going to handle the bird regularly use binoculars to take a close look at the bird, regularly, paying particular attention to any swelling, redness or soreness of the feet.


Broken Legs

Broken legs are regularly seen in raptors. The vast majority of birds suffering broken legs are first year birds, they are startled and bate off the perch which they are tethered to. Young birds, both when they are first jessed up, and until they are completely manned, should not be tethered in a site where humans, birds or animals might alarm them. If a young bird shows a particular tendency to bate then an elasticated leash (bungy) should be used. Such a leash should be strong enough to with stand considerable trauma, without running any risk of breaking, but which allows a small amount of 'give' so as to avoid the sudden 'jerk' as a bird bates away from the perch. As a safety measure a further leash should also be in place which will only come into action should the bungy give way.

Very often these birds are seen standing quite peacefully, on one leg with the damaged leg pulled up against the body. The position demonstrated is quite natural, and is often mistaken for a bird just resting one leg. This point should be born in mind when examining a tethered (especially first year bird) When a fracture occurs in this manner, it is almost invariably the tibio-tarsus which is fractured, at the junction of the first and second 'third' of the bone. Such fractures are best repaired by internal fixation, and should be taken as soon as possible to a veterinary surgeon. If the journey to the vet is to be delayed up to 24 hours, there is no need for any temporary action. If for some reason the delay is longer (this should not arise), then an aluminium finger splint (as supplied in the first aid kit), can be applied. The splint is bent at appropriate distances to correspond with the normal joints of the limb, and is applied to the front of the leg. It is kept in place by firmly (but not tightly) applied tape. Some form of padding, such as a layer of cotton wool should be applied under the splint.

Fractures of the femur (thigh bone) are relatively rare and almost always occur as a result of a hunting accident. Typically a bird grabs a rabbit or some other quarry just as it descends a rabbit hole. The rabbit keeps going, so does the bird (still in flight), between the two the leg gives way.

Swollen LegsThere are a number of factors which will give rise to swelling of a leg. The latter include broken legs,

strained tendons, infection, bruising, thorns. All these need to be judged and treated on their own merits, however it is of paramount importance that if the leg is swelling that no ring, cable tie , jessie etc. (or even a scab) should cause a constriction of the lower limb. It is amazing how even a very slight swelling, (especially on a small bird such as a sparrowhawk), can lead to a reduced space between leg and ring. If not seen and remedied very quickly this will lead to a loss of blood supply, gangrene and loss of a leg or foot. Some falconers seem to like to adorn their birds leg with as many items of furniture as possible. Often two rings are still present (i.e.. male & female), bewit, jessies, cable tie etc. It is a good safety measure to minimise the items on any leg, and if possible use a tail rather than a leg bell.


Parasitology

Parasites of RaptorsAny parasite relies on survival of the animal in which it lives in order to survive itself. It is therefore not

normal for a parasite to lead to the death of the host in which it lives. Under normal circumstances parasite and host will live in a balanced harmony. The exception arises when the normal hosts resistance against the parasite, which usually keeps it's infestation under some semblance of control, is reduced allowing the parasite to gain the upper hand. Such situations arise when wild birds are short of food, following migration, accident, injury or during extended periods of inclement weather. For the falconer's bird training, chilling, accident, or other causes of stress may trigger off the same situation. There are exceptions to this rule, where even a small number of parasites can cause disease, this arises where the parasite only needs to live in that host for a short period, in order to complete a life cycle, this done he does not mind if the host becomes diseased and dies. Recently parasitic diseases have been increasing in incidence in captive bred birds, this is as a consequence of increased levels of exposure to the parasite, as a consequence of increased contamination of the aviary by the parents.

External ParasitesA large ecto parasites infestation on a bird is typically a sign of the bird being ill for other reasons, as any fit

bird will usually control it's own parasites. So rather than treating the parasite alone, one should always look for a further cause of illness.

Hippoboscids (keds or flat flies) are perhaps the commonest parasites of raptors. They are blood suckers, although they rarely cause any significant blood loss. There is however now evidence to suggest that they can and do carry blood borne parasites between one bird and another. In particular the blood parasites 'Leucocytozoon', 'Plasmodium' 'Sarcocystis' as well as other blood born infections. In the United Kingdom such blood borne parasites are rare, however in warmer climates such as USA diseases such as malaria are highly significant. After the warmer summers of 1994/95, the incidence has increased, affecting birds aged 3 - 5 months, to date owls (especially snowy), harris hawks and gyr falcons have been affected. In one case, the affected bird had caught a magpie only 9 days earlier, which had a heavy infestation of hippoboscids, in time it became evident that these had carried a blood parasite infestation, which caused a dramatic and fatal infection of the harris hawk in a very short time.

Lice are also a common ecto parasite of raptors. Lice feed off skin debris and feathers, they do not however survive off the host for long, and hence treatment with routine insecticide preparations is relatively easy.

Conversely Dermanyssus gallinae the 'Red Poultry Mite', does survive off the host for considerable periods. This mite lives in crevices in the wood work and usually only comes out at night to feed, as such a feather plucking bird may appear free of parasites when examined during the day, whilst the same bird is crawling with them at night.

Any ecto parasite which actually sucks it's hosts blood can be easily and readily controlled by use of the cattle wormer 'Ivomec' (MSD AgVet), however this will need to be diluted, doses and suitable diluants can be arranged by your veterinary surgeon.

Other ecto parasites are best controlled by the use of insecticides, however great care must be taken that only safe preparations are used. Some sprays contain either active ingredients or propellants which can lead to toxicity or irritation to the air sacs. The new cat and dog flea preparation 'Frontline' has proved safe and effective in over 100 birds on which we have used it. It appears to be not only more effective but also far safer than previously recommended ectosparasite preparations.

Internal ParasitesMany bird keepers, falconers and rehabilitators simply worm their birds annually or when they are handled

and believe that all is then well. This concept is seriously floored, and can on occasions lead to serious repercussions.

Fluke: fluke are a relatively common although usually non pathogenic parasite of raptors. They may inhabit the small intestine or the bile ducts. Diagnosis is made only on faecal examination, and although usually non pathogenic, when found treatment should be given. The drug which is most commonly used is rafoxanide at a dose of 10mg/kg, or praziquantel (droncit) 5 - 10mg/kg daily 14 days or chlorsulon (Curatrem) 20mg/kg by mouth 3x at 2 week intervals. Both the diagnosis, advice on treatment and the drug will be available from your vet.

Tapeworms: tapeworms are a relatively common parasite, but are rarely pathogenic. Clinical illness will only occur in situations in which there is very heavy infestation, which can lead to an obstruction of the small intestine. Treatment is by the use of Praziquantel (Droncit, Bayer), which is available in injection or tablet form, and birds should be dosed at 5 - 10mg/kg or chlorsulon as above.


Roundworms: these are the largest and most significant group of endo parasites. The group includes the 'Syngamus trachea ' and 'Serratospiculum sp.', which affect the wind pipe, and air sacs respectively. Both will cause respiratory signs in infected birds, however in both cases it is particularly important that the diagnosis is made prior to treatment being given. In the case of Syngamus even after the worms are killed they will remain in the airways for up to six weeks slowly rotting away causing respiratory signs and occasionally pneumonia in the meantime. Serratospiculum is most commonly found in this country in imported birds (coming from warmer countries). The worm itself does not usually cause any clinical signs, and may live in the air sacs happily for several years. However if the worm is killed it will rapidly putrefy often causing a severe air sacculitis and death. If the worm is diagnosed then the preferable treatment is to treat the bird with wormer daily for 14 days and then to surgical removal of the worm from the air sac.

Drugs which have been used in the treatment of roundworms include piperazine, levamisole, benzimidazoles (e.g. Panacur or Mebenvet or Pyrantel) and ivermectin (Ivomec). Some of these are now old fashioned and ineffective, others have very narrow safety margin and can be dangerous, others are potentially toxic at certain times of year (especially during the moult), others are safe.

Protozoa: This group of parasites includes 'Trichomonas gallinae' the agent which causes 'Frounce'. The most common source of infection is from pigeons. Many falconers believe that just because the pigeon looks clean, or by avoiding feeding the crop the disease can be avoided, this is not invariably the case. Even the breast muscle itself can carry the infective agent. Any pigeon fed to raptors should be frozen first as this freezing kills off virtually all the organisms. The disease is seen as white plaques in the mouth, throat or crop. However the condition must be differentiated from infection with Capillaria, Candida or Vitamin A deficiency or owl Herpes Virus (in owls). The differential diagnosis can be easily made by your vet. Treatment is with Carnidazole (Spartrix) 25mg/kg once. This single treatment as opposed to the previously recommended daily treatment for 5 days makes therapy a lot easier, particularly for young wild or captive birds still on a nest being fed by the parents.

The same group of parasites also includes coccidia, which may be present and cause or not cause disease, depending which exact species of coccidia is involved, likewise if disease does occur the clinical signs and treatment required will be different. Coccidia have been recognised as an increasing due to a build up of infection in captive breeding aviaries. The disease affects primarily young birds, prior to their having developed any immunity of their own. The condition is treated with Toltrazuril (baycox) at 10mg/kg once daily on three consecutive days, or Clazuril (Appertex) at 5-10 mg/kg once daily on three consecutive days. Giardia and Hexamita are two further protozoa which can cause clinical disease.

Coccidiosis in Merlin ; as most readers will be aware, coccidiosis in merlins has been an increasing problem for a number of years. In a paper presented at the Small Falcon Conference in 1991, it was shown by this author to be the single largest cause of death in captive merlins. Since that time the condition has increased in incidence, and in the last two years has also been shown to affecting considerable numbers of goshawks and peregrines. Although the therapeutic regime recommended above is effective in preventing death in affected birds it is still not effective in totally eradicating the organism from the birds system. As a consequence some months later the bird will start to shed the organism again, (although not becoming ill itself). This shedding will lead to considerable contamination of the aviary, leading to the future infestation of other birds. It is generally only young birds, or those who are ill for any other reason who will actually succumb to the disease. this disease is subject of considerable on going research at the Clockhouse Veterinary Hospital. We are still happy to test free of charge mute samples from any captive merlins, so long as the keepers are prepared to send samples on a regular monthly basis. It is only by this continued research that we hope we can finally get on top of this disease which has serious future implications for the captive breeding of raptors, not only in the UK but also in other parts of the world.

Above all the important fact that all keepers should realise is that no one treatment will be effective against any more than one of these groups of parasites. Treatment will lead to a false sense of security, may be unnecessary, and more over can be dangerous. Prior to any treatment a faecal sample can be quickly and cheaply examined by your veterinary surgeon who can the advise and supply the most suitable agent.

At the Clockhouse Veterinary Hospital, we run a fast, efficient and cheap service for the testing of mute samples for parasites. Keepers sending a sample are requested to telephone after 12 noon on the day (week day), that we receive the sample, and we will inform them of the result. The cost of this service is £ 6.50 + vat, a discounted to £5.75 + vat for more than 6 samples at any one time.

Water-logging Water logging can potentially lead to the death of a bird.

The penetration of water into plumage can result from accidental soaking as a result of being immersed in water, often as a result of a prey species becoming submerged. Alternatively it can occur as a result of a bird becoming caught in a sudden rain storm. The latter situation can often happen to an injured wild bird, especially if it is restricted to movement around the ground on account of it's injuries. Equally it may be seen during a day's falconry, perhaps whilst in the middle of a grouse moor where no shelter is available. The same result can arise as a consequence of a bird having a non functional preen gland (situated just in front of the tail). The preen gland produces an oily substance which birds use to assist in water proofing their feathers. Similarly even if the preen Page 28 Copyright Neil A Forbes FRCVS 1996

gland is functioning a bird may loose it's water proofing as a result of oils (natural such as 'fulmar oil' or artificial such as petroleum) or detergents coming into contact with the plumage. (This is one reason why oily ointments and creams should not be used in the treatment of birds unless this is essential).

Once the feathers have become soaked there is a very rapid loss of heat from the bird. The birds' plumage should act as the birds own personal 'duvet', providing a layer of static air which prevents heat loss by convection and conduction. A bird is small it has proportionately more surface area from which to loose heat, in comparison with the body volume with which to produce heat, furthermore they have a higher body temperature than mammals. As a result of these two factors heat loss is far more serious for a bird than any mammal. The resulting 'hypothermia' (drop in body temperature), will lead to shock, collapsed circulation and often to death. The wet bird must therefore be immediately taken out of any prevailing wind, wrapped up (using exposure blanket - see first aid kit) and dried. Ideally the bird should be placed in a warm environment, if possible as high as 75-85oF. Veterinary attention should be sought, in order to control the circulatory collapse, hypothermia, shock and the frequent secondary infections. The use of an exposure blanket (as in first aid kit), kitchen foil or plastic bubble wrap is useful. Although the exposure blanket is the most useful, care should be taken not to overheat or cook the patient.

The problem of heat loss from birds is so great that even the plucking of feathers, and disinfection of the skin prior to surgery by a surgeon, has to be carried out in moderation and with great care.

Drowning

The drowning of birds is not as uncommon as one might expect.Both wild and captive raptors show an alarming ability to commit suicide in a few inches of water. Certainly the design of water bowls and any disabilities the bird may have seem to be strong predisposing factors.

In the event of being present when a bird is drowning one should initially swing the bird upside down to clear any water which is actually obstructing the airway. If the bird is not breathing place it on it's back and by moving the wings, as in flight, the birds single lung will be ventilated to some extent. Not all the water needs to be removed in order for the bird to survive. The main cause of death, however, in freshwater drowning is due to important metal salts being lost from the blood into the water in the lungs and air sacs. The latter salts are essential for heart and other muscle function, hence as deficient blood reaches the heart, usually only 15-30 seconds after submersion, the bird will die. Any bird which inhales any water, however little, should receive prompt veterinary treatment, even if it appears well, as damage to the lining of the lung can lead to a secondary effusion of fluid into the airways some hours later. Inhalation of water, even droplets, can also often lead to secondary pneumonia or air sacculitis.

Oh yes... and if the bird is alive do not forget the risk of hypothermia as a result of water logging..

Electrocution

Electrocution is a significant cause of death in larger birds of prey. Both the Griffin Vulture in Israel and the Cape Vulture in South Africa have shown to be declining partly due to fatal contacts with electricity cables. The United States and South Africa have lead the world in adapting their electricity pylons to minimise the risk of such losses. Electric shocks can lead to both superficial and deep burns. Such injuries should receive veterinary treatment immediately. Any bird which has received a non fatal electrical shock should be given shock treatment immediately. If the bird can swallow or keep fluids down, glucose saline should be given by mouth. The bird should be restrained in a stocking type support if it is suffering from fits, tremors or inco-ordination and taken straight to a vet.

Bites from PreyBirds flown for falconry, will sadly often be bitten, kicked or scratched by prey species which they have not

been over powered immediately. Any bite wound is potentially serious. Unlike the majority of humans, squirrels, rats and the like unfortunately do not clean their teeth daily, as a result the teeth are almost invariably infected and dirty. This being so, a bite wound will inevitably be infected. Any such wound should initially be washed in an antiseptic solution (e.g. pevidine). The wound may look small and innocuous, however the teeth may well have sunk deep into the tissues, in effect, injecting bacteria deep into the body. Any bite wounds so placed deep into tissues should be presented to a vet for assessment and likely antibiotics. It would be fool hardy to suggest that every squirrel bite should be seen by a vet, as many Harris hawks would be banging on our front doors daily. However the principle should be remembered that they may well be infected. If deep into the leg or breast they will need antibiotics, if relatively superficial on the feet, then they should cleaned painted with a topical disinfectant such as pevidine (as in first aid) soon and then observed carefully, and any sign of swelling, redness or heat. If these signs develop the bird should be taken straight to a vet.

Conversely any breach of the skin in a falcon, will almost certainly require antibiotics, as any bumblefoot infection is so much more serious in the falcons than in short wings or buzzards.


Rips, cuts and abrasions.

Traumatic injuries are amongst the commonest emergencies which may befall either a wild or a captive raptor.

They may arise as a result of gunshot, traps, predation by same or other species, collision with stationary objects or vehicles. Many such injuries prove fatal, others escape with more or less severe injuries.

The first aid treatment of any wound is similar in principle to that which many will have learned in basic human first aid courses. The main difference is that a bird is very small compared with a human, and hence blood loss, shock, hypothermia etc., will all have a more serious effect.

Any wound should be examined carefully, and gently so as to ascertain the extent of the damage. If there is still haemorrhage (bleeding) this must first be controlled. On no account should any clot be removed as this will often lead to further bleeding. More detailed notes on haemorrhage appear above under the section on the treatment of shock.Control of haemorrhage can be achieved by the following means:-1) Local Pressure- Sustained pressure with a finger, plus cotton wool or haemostatic swab for 3-4 min.2) Tourniquet - If one can see the blood coming straight form one severed blood vessel, then if one can catch this with a pair of forceps, pressure may be applied to it, the end may be twisted around or a sterile cotton suture may be applied. Such a process may well be beyond most lay persons, and should only be carried

out in an emergency. If no single point of bleeding can be found then in an emergency a tourniquet may be applied to the limb above the point of bleeding. This procedure should not be used unless the birds life is at risk, and should not be kept in place for longer than 15 minutes, as it can lead to permanent damage to, and even loss of the limb.3) Cautery -Bleeding may be controlled from a small pin point wound or lost claw by the application of thermal (i.e.. heat) or chemical cautery. The first aid kit contains a vial of potassium permanganate crystals, a minimum amount of water may be added to these and the solution touched against the bleeding surface for a short period only.

Wounds may be classified into several groups:Type Possible Treatment

1) Superficial abrasions skin unbroken. Wound powder/antiseptic solution or cream2) Small fresh clean cuts As above3) Small contaminated cuts Antiseptic washes & Antibiotics e.g. bites, crabbing injuries4) Large clean cuts As for 3 plus sutures5) Large contaminated wounds Antibiotics, immediate or delayed sutures + drains6) Any wound with severe bleeding As for 4

Types 4,5 & 6 will definitely require veterinary treatment, in many situations type 3 may also benefit from it.It is not advisable to apply any products other than a simple non adherent dressing to wounds which are

going to require referral to a vet, as many topical applications will actually interfere with the treatment which is indicated. In view of this the choice of topical applications is far from simple, you are advised to seek advice from your own vet, bearing in mind the situation which presents at that time.

Concussion

Birds flying into static objects such as glass windows may suffer from a number of varied injuries

The initial treatment for any of these cases should be the general shocked bird treatment. In other words, glucose saline by mouth, (if the bird is unconscious, prop the head up above the level of the crop, so that fluid from the crop cannot reflux into the throat and be inhaled), warmth, dark and quiet. After an hour re-examine the bird and asses the damage incurred.

In some cases the bird will simply be stunned and appear completely back to normal 15 minutes later. Before simply releasing the bird check that it's balance and co-ordination is normal, and also that it's eye sight appears normal. As explained before birds do not necessarily show a pupillary reflex (i.e.. constriction of the iris when a light is shone at it), however if it is present then all is well. One may have to try the 'menace response', i.e. advancing a hand or finger near the eye and watching for evasive action. Both eyes should show some response, and it should be equal. Any asymmetry, or lack of response, should be considered significant and the bird should be seen by a vet.


Other injuries which may occur include concussion, cerebral haemorrhage, nerve damage to spine or extremity, fractures of cranium, jaw, neck, coracoid or furcula (see previous diagram of skeleton). Any such more serious injuries must be referred to a vet, as soon as possible.

'Crabbing'

Grasping of one bird in the talons of another is a sadly common injury. It usually occurs when birds are flown in a cast or when one bird is being flown whilst a rival is still tethered to a perch/cadge. This can happen out of the blue, when both birds have been quite happy in each other’s presence for years. Secondly it can occur when two birds are left either too close to each other on perches or on a cadge. Thirdly it can often occur when an ungrateful or unwelcoming female, does not relish the thoughts of conjugal bliss and decides to attack her would be husband.

The actual incident does not usually last for long, if the birds still have hold of each other, then grasping the neck of the attacker will usually persuade the bird to turn her evil thoughts in your direction and to spare her poor unsuspecting husband.

Any wounds should be cleaned, and any feathers which have been forced internally, should be pulled out. The wounds should be cleaned with antiseptic (e.g. pevidine see first aid kit), and the bird referred to your vet for antibiotics. These are always indicated after an incidence of 'crabbing'.

Emergencies with chicks/neonates.From the point of view of rehabilitators, one hopes not to have to handle neonates, except in exceptional

circumstances. The so called 'orphaned chick' is the bain or any rehabilitators life, and a cause of great frustration. The public must be educated to leave these chicks were they are found, hopefully lofted up off the ground, away from cats and other predators, so that the parents can continue to care for them.

It is not unusual for the odd chick hatching in a brooder, to do so with the yolk sac still outside the body. Initially (with very clean hands), one should try very gentle massage on the yolk sac, pushing it towards the umbilicus, in some cases the sac can be persuaded to enter the abdomen to it's correct position. Antibiotics should be given after treatment.

If return of the yolk sac is impossible, or if a blood vessel on an exteriorised yolk sac becomes ruptured then a sterile suture (boiled cotton) should be applied with great care around the neck of the yolk sac as it enters the abdomen, then he external part cut off.

Distortion of Legs or FeetOne of the commonest disorders which affects chicks is mal-positioning or alignment of one or both legs,

feet or toes. There are a whole range of factors which can cause this.Firstly the physical nature of the substrate of the nest or brooder. If the surface is smooth the legs are

bound to spread from the hips (i.e.. do the splits). This is easily remedied by placing shackles (made of some suitable paper or fine weave dressing tape, e.g.. micropore) on the legs and at the same time improving the floor surface. In severe cases a towel may be rolled in from each end to meet in the centre. The whole towel is then turned over to reveal a crease, between the two rolls, into which the chick is placed. This has the effect of supporting the chick with its legs in a natural position. Alternatively the chick can be placed in a padded portion of plastic guttering.

Nutritional problems can give rise to poor bone development. This problem can be seen because of an in proper diet fed to the chicks, or a poor diet or metabolic disorder affecting the hen prior to initial egg laying. It seems initially difficult to comprehend that a bird can find sufficient calcium to produce an egg shell, but may have placed insufficient calcium into the yolk itself.

We have seen this situation in very elderly parents who were suffering from concurrent kidney failure, or other metabolic disorders. The latter condition leads to an increased loss of calcium from the kidney, and hence hypocalcaemia, although a normal egg shell was produced. The situation revealed itself by greatly enlarged growth plates (in particular on the tibiotarsus and metatarsus), and laterally rotated legs which failed to develop naturally. A more subtle form of the same disease occurs where the chicks develop twisted, bent of rotated legs (one or both). In such circumstances the chick has often suffered from a bone growth deformity named 'tibial dyschondroplasia'. This is most commonly seen in the mildly calcium deficient chick. In the author’s experience, excluding situations where chicks were fed on a poor diet, all other affected chicks were from second or


subsequent clutches. This point emphasises the importance of greatly increasing the dietary calcium content of birds after a first clutch if you wish them to recycle.

If the dietary deficiency is in the chick’s diet, one tends to find that the chicks bones are very soft, they can be bent by simple digital pressure. It is most important to remember that a natural diet is a whole carcass. When feeding young birds one must use minced whole birds or mammals and not minced meat alone. If the ailment is rapidly diagnosed then the situation can be reversed by simply correcting the diet and for a period supplementing with a calcium and vitamin D3 supplement, such as Nutrobal (Vetark), which is available from many vets or pet supplies.

Vitamin D3 is essential for the metabolism of calcium by the body. This vitamin is synthesised by the action of ultraviolet light on the skin. Vitamin D3 is produced in the secretion of the preen gland, and during preening it is thought that a certain amount is ingested. If adult birds, or chicks are maintained in artificial light for any period of time, this vitamin may become depleted, resulting in calcium deficiency although the dietary calcium content is adequate. The same occurs if birds are in aviaries with solid, perspex or glass roofs as any of these will tend to eliminate the ultraviolet light.

Three further vitamin deficiencies can lead to leg deformities, these are Vitamin E (in conjunction with the mineral selenium), Vitamin B (usually Riboflavin) and Vitamin A. Often the signs of these three deficiencies can be confusingly similar, and hence treatment with all vitamins by injection is recommended, if any signs are seen. These signs can include a backward tipping or rotation of the head, but more commonly a twisting of one or both legs. Angulation of the leg will often return to normal within hours of treatment. All three vitamins are given by injection, and will need to be prescribed by a vet.

The mineral manganese is reported to cause similar leg rotations in poultry, although such a deficiency seems less likely in raptors and has never been reported in them.

Most people think of bone as being a rigid hard structure, where as in fact it is malleable, and changes in relation to pressures which are put upon it. For this reason it is most important, that if a chicks leg or any other bone appears to be in an abnormal position that it is either referred to a vet, or at very least that the bone in question is tapped in some way such that it is then maintained in a normal position. Even apparently bizarre abnormalities, can often be returned to normal within days by such treatment, in particular in chicks as growth and bone development is so rapid.

Regular complete examination of developing chicks is of paramount importance. Many injured chicks are referred to vets, where the injury has been obviously present for some period, occasionally weeks. This occurs because chicks in a nest who continue to feed, are assumed to be developing normally. Such cases may involve broken legs, twigs forced between leg and closed ring etc.,. It cannot be over stressed the need for constant through vigilance. Do not assume a chick is normal just because it puts its head up and screams for food. When designing an aviary it is of paramount importance that the keeper can fully visualise the nest ledge.

Reduced Weight gain or Weight Loss.

Chicks should make a steady weight gain doubling their weight by day ten. Weighing chicks is of course only relevant to hand reared birds. Sudden reductions in weight gain are usually associated with infections, which are most commonly caused by bacteria. As such they may well respond to antibiotics. The latter must be prescribed by your vet, and should be administered as soon as the chick shows any sign of weight loss or reduced appetite. The single most important factor in the care of young birds, in particular when under 10 days of age, is care in heating and feeding in order to try and prevent infection in this critical period whilst the chick has little or no immune system. Infections whilst immune incompetent are greatly reduced if not eliminated by feeding a good quality avian probiotic such as Avipro or Avipro Paediatric (Vetark).

Impacted ProventriculusYoung chicks are often unable to cast properly, for this reason they should not be given casting, nor should

parents be given it, as they will often feed it to the young, oblivious of the risks. The signs seen are usually of an older bird, 10-20 days who has an enlarged abdomen, (a firm mass may be palpable behind the ribs), who shows a reduced inclination to feed, or who may be vomiting back it's food.

Initial treatment should involve giving lactated ringers solution, or liquid food such as 'Reanamyl' (Virbac), Hills A/d, Critical Care Formula, Polyaid, Day One. This liquid should be given by crop tube at a rate of 1ml per 50g chick every 2 hours. Often this fluid alone will make the chick feel better, and at the same time soften the casting sufficiently for the bird to eject it. Most importantly by continued force feeding, the chick will grow in size to a point where it can safely cast the pellet.

Crop Stasis & Sour CropYoung hand fed chicks often suffer from these conditions, they usually arise due to insufficient stimulation

prior to feeding, cold or inappropriate food, in proper feeding methods or infection. A further feed should never be given to any bird until it has put over its previous crop. Once the food is put over from the crop to the proventriculus, the stomach acids start to act and hence prevent any putrefaction. However if excessive food sits in the crop for any period of time, due to the warmth and lack of acid it starts to go off. This process rapidly causes Page 32 Copyright Neil A Forbes FRCVS 1996

a 'toxaemia' i.e. poisonous toxins are produced which enter the blood supply, rapidly leading to death. Treatment involves emptying the crop if possible, 'Emequel' (Beecham Animal Health) to stimulate gut activity, fluid therapy i.e.. 'Hartmans/Lactated Ringers' solution 1/2-1ml per chick hourly, and antibiotics.

Collapsed or Lethargic ChickThese are frequently seen and can arise from a number of causes. These include infection, starvation, impaction, dehydration, chilling or over-heating. The initial treatment what ever the cause will be fluids by mouth, glucose solution, antibiotics and rectification of the husbandry fault.

Infection in Chicks

This can arise from a number of possible sources. If very young chicks are affected, infection may have entered them from their mothers ovaries. This is known to occur with Salmonella enteridis, and a number of other serious pathogens.

Or it can occur immediately after the egg has been laid. The egg shell consists of a large number of microscopic pores, which allow air and very small particles to enter. As the egg cools it draws air from around it into the egg itself. Within the first three minutes after an egg is laid, a whole range of organisms such as E.Coli, Aspergillous sp. etc. may enter. Thirdly infection can enter during incubation, whether natural or artificial. This is particularly likely if their is an infected, or addled egg in the nest, or if the nest or incubator itself is dirty. In this situation dirty does not mean visible dirt, but bacterial contamination. Fourthly infection can occur at hatching or soon after, either by contamination of the umbilicus/yolk sac, or by contaminated food. Many breeders take very great care over hygiene and cannot comprehend how infection can possibly have been a problem. It should be remembered that we all have infection around us all the time. Even if you scrub your hands with disinfectant, you will not sterilise your hands, all you will do is reduce the bacterial burden. A young chick for it's first ten days of life is what is termed 'immune incompetent', i.e.. it's immune system does not function adequately. In view of this any bacterial burden however low is a risk. Some birds get over this themselves by the production of crop milk which they give their young. It appears that for some of these species (such as black vultures) that this is an essential ingredient for infection free development. For these species such crop milk may be harvested from the parents (i.e. vulture vomit) and given to the young. For the majority the use of high doses of probiotic and vitamins ('Avipro Paediatric' Vetark) in the food for the first 14 days helps greatly in reducing gut and blood infections in young chicks, as well as increased growth rates.

Conditions Affecting Adult Birds in the Breeding SeasonIt is paramount that all areas of a breeding aviary can be observed at any time, both birds should be observed on a twice daily basis, if one is not immediately apparent then it must be checked out. A reluctance to disturb breeding birds is no excuse for not checking they are well at all times. The nest ledge should be sheltered from the elements (wind, rain & direct sunlight). All breeders should be aware of the potential for attack of the hen pecked male by his mate, this is of course a particular risk with goshawks and merlins. Reinforcement of confidence and the ethos of being a 'provider' in the male, and the instillation of this concept in the female will help to achieve this. This is best achieved by lowering the condition of both male and female prior to the breeding season. After this the male must be feed at frequent intervals often 5-6 x daily. At this stage the birds are often best kept in adjacent aviaries. The sound of the male being constantly fed, reinforces the concept of him being a food provider, this raises his confidence, and his spouse realises that perhaps he is of some value after all. If birds are seen to crab each other, then the injured bird must be treated, even if this means disturbing the pair. As with all crabbing injuries, deep seated wounds with a narrow entry point, frequently lead to abscessation at depth in the tissues. Injured birds should receive antibiotics for at least three days.

Egg lethargy :- this is a natural phenomenon, which is related to the passage of an egg through the pelvis, this leads to substantial pressure on the internal organs, as well as a potential dip in blood calcium levels at this stage. Many female birds will look heavy and uncomfortable, however they should not be sitting around on the floor of the aviary. If the latter is seen this usually denotes egg binding which is a pathological and dangerous condition. One should know one's birds, with respect to species, age and individual breeding record. One should witness the laying of each egg, and hence be aware of when the next one is due. If an egg is late & the female is uncomfortable, then there is even more reason to suspect egg binding and intervene.

Egg Binding :-this is a common condition in egg laying females. In essence the problem occurs when an egg becomes lodged on it's passage down the oviduct. This occurs most commonly after the pair have been disturbed, if the female is calcium deficient, when there has been a cold prevailing wind or other unknown factors. The hen looks depressed lethargic, fluffed up and is often seen siting on the floor of the aviary, frequently demonstrating


weakness in the legs. Such a bird should be carefully caught up, in a manner such that the egg, in her abdomen, does not become broken.She should then be placed in a warm, humid environment (eg in an enclosed box with a heat pad), if the egg is not produced within 1 hour, the bird should be presented to your vet. The bird should then be treated with calcium and (oxytocin) vasotocin and PGE gel, in order to help stimulate oviduct contractions. If this is unsuccessful, then the bird must be anaesthetised, fluid therapy should be given to help combat shock, the egg should then be lubricated and removed, intact or following rupture, if necessary by caesarean section. If it can be removed wholemeal, then this should be the aim. If the egg is still high up the oviduct and hence soft shelled, the egg should have it's contents sucked out of it, the residue will later be passed.

Egg Peritonitis :- following egg binding, egg peritonitis is a common sequel. Equally it may also occur after any shock or inclement weather. In this situation when a follicle (yolk) is released from the ovary, instead of entering the oviduct and passing down to the cloaca it falls into the abdomen leading to a peritonitis. In this situation you see a very sick bird very quickly. If the bird is to saved, she must receive fluid therapy and powerful antibiotics rapidly, that breeding season, and perhaps all her breeding career are now over, great efforts must be made to save the birds life.

Prolapsed Oviduct :- this too is an emergency situation. In this case the bird is trying to pass an egg or has some irritation or infection in the oviduct and as a consequence is straining hard, and has pushed part or all of the oviduct out. This problem rapidly leads to very severe shock, and the condition requires rapid through treatment if the birds life is to be saved. If the oviduct is clean and undamaged then it may be pushed back inside, then a suture is placed around the cloaca to keep it in, if of course she then attempts to pass an egg the suture must be removed. However pushing it back in alone is not sufficient. Surgery must be performed, the abdomen is opened and the oviduct is also pulled back from inside, if this is not done the bird will be left with a section of oviduct doubled up on itself inside. The latter section will have an impaired blood supply, that section will then die, causing the death of the bird. If instead the oviduct is diseased or damaged, then the whole oviduct must be removed. Surprisingly if the oviduct is removed, the ovary can be left in situ no further follicles will be released, as the stimulation for ovulation comes from the oviduct.

Causes of Breeding FailureDead in shell and death of chicks:- Chicks will fail to thrive grow and survive for a number of reasons, these can be broadly divided into the following groups. Infections (bacterial, viral, fungal or parasitic), nutritional and traumatic. Many such losses can be prevented if sufficient thought and planning is made in advance.

As far as infections are concerned these may arise at any one of four key points along the production process. Firstly the egg yolk may be infected even before the white or the shell is added, as a consequence of infection passing directly from the ovary, into the yolk. Salmonella enteridis is a good example of an organism which is passed from hen to egg, one which made Edwina Curry very rapidly famous. Secondly as the egg is laid, it cools in so doing it draws infection in through the pores in the shell, leading to infection of the egg. It is known that bacteria such as E coli and Salmonella sp enter an egg within three minutes of it leaving the cloaca. Thirdly infection can enter the egg during incubation, whether naturally or artificially brooded. Fourthly chicks are known to be 'immune incompetent' for the first 10 days of their life, during this period they are highly susceptible to infections.We will consider each possibility in turn in an attempt to reduce the chances of their occurrence.

If one has had a number of chicks, either dead in shell, failed to hatch, weak with poor feeding and growth rates, or fading within the first 10 days of life, one must try and evaluate where the problem has arisen so that it can be prevented in future.In situations where the egg is infected before or immediately post laying, one should suspect that one or both parents might be carrying a latent infection which has been passed on. In such cases typically all or the majority of the clutch are affected. The options are to screen the birds, taking repeated faecal samples for analysis. However this is fraught with false negatives, because the bird may shed the organism either intermittently or not at all. Although one does not recommend prophylactic medication, an alternative is to treat both parents for a period of 5 - 7 days some 2-3 months prior to breeding. Antibiotics should not be used, if at all possible, near the time of laying as they are often responsible for lower egg weights, chick weights and slower growth rates of chicks. Secondly the nest ledge should be kept as clean and dry as possible. Decaying organic material such as leaves, straw & hay should never be used as aspergillous may well enter the eggs, as well as affecting the parents. If bantams or other foster brooders are used only first and second year birds should be kept, as the incidence of avian tuberculosis, increases greatly after this point. Mycobacterium avium which causes the disease can cross the shell and enter the egg. If one is using artificial incubation, great care must be taken in collection of eggs, using a clean receptacle each time and handling the eggs as little and as gently as possible. No cracked, damaged or particularly dirty eggs should be placed in an incubator with others. Eggs should be regularly candled so that any clear eggs or dead in shells can be removed before there is any chance of them decaying and infecting healthy chicks. An all in all out policy should be used if at all possible in other words one should not keep adding eggs during a season simply removing them as they pip, instead one must allow the opportunity to fumigate the incubator during the season, if it is to be used repeatedly. The traditional method of sterilisation is with a


combination of potassium permanganate and formaldehyde. This method not only allows us all to relive childhood pranks with chemistry sets, but is also effective. As previously stated chicks are immune incompetent for the first 10 days of life, in other words they are unable to fight off any infectious disease. However careful you are in the hygienic preparation of the chicks diet, it cannot and will not be sterile, so inevitably some infection will enter the gut, where it may well cause infection or enter the blood stream leading to a septicaemia (blood poisoning) and likely death of the chick. The chances of this whole scenario can be greatly reduced by feeding the chicks for the first 15 days on a good quality avian 'probiotic'. This is a preparation which contains high levels of 'useful' bacteria (Strep faecalis & Lactobacillus spp), which swamp the gut, preventing any significant growth by harmful bacteria. By using such a product one will reduce the incidence of neonatal losses and increase their initial growth rates. Many suitable probiotics are now available, the one used by the authors is 'Avipro paediatric ' (Vetark).

Virus infections :- of chicks is now more common, principally because of the increased rates of such infections in our birds food chain. Such infections typically lead to weak poor chicks which often die before they are 3 weeks old. One can only be certain of avoiding these by feeding non avian derived food, as relatively few of these agents cross the species barrier.

Fungal Infections :- (ie Aspergillous sp and Candida sp), infection with these organisms is not uncommon in chicks. Some species such as Gyr Falcon, Goshawk, Golden Eagle, Black Sparrow-hawk, Snowy Owl are particularly susceptible to aspergillous. Two factors must be considered, firstly no decaying vegetable material should be or have been in vicinity, (ie never use an old horse stable, keep the compost heap well away, do not use shredded wood bark), secondly minimise all possible stress. The organism is 'ubiquitous' ie it is found everywhere, so for the sensitive species who only require a low rate of infection to cause the disease, it is the stress of manning, transport etc which will trigger off disease. When dealing with particularly sensitive valuable birds it may well be prudent to treat the birds prophylactically before any unavoidable stressful event occurs.

Candida is a yeast infection which occurs most frequently after sudden changes in diet, or antibiotic therapy. Occurrence can be avoided in either situation by giving the bird probiotic for the duration (plus five extra days), of the risk period.

Parasitic Infections :- these commonly include Trichomonas which causes 'frounce ', roundworms such as Syngamus trachea (gape worm) and Capillaria and coccidia. Many other parasites may be found, but the latter are the commonest ones in young raptors. Taking each in turn 'frounce' may be avoided by not feeding fresh pigeon. Any pigeon fed should be frozen for at least 24 hours. Frounce, Capillaria and Candida may all cause identical clinical signs ie. poor appetite, food or head flicking, regurgitation. If treatment is to be effective an accurate diagnosis must be made. Infection with gape-worms occurs either by ingestion of a transport host by the affected bird or direct ingestion of infective larvae, ie an intermediate host is not required. Transport hosts are typically snails, slugs and earthworms. In view of this the species most commonly affected are broad wings such as red tail, buzzard and ferruginous. Affected birds have an audible croak or wheeze as they breath, however similar signs may be seen with bacterial infections or aspergillous. Do not treat the bird without having the diagnosis checked, because even if you are correct in the diagnosis, any wormer given will kill the worms who will then remain in the wind pipe and lungs until they decay, which may take 4-6 weeks. During this period the birds clinical signs will continue, so you will not know if you have correctly treated the condition, antibiotics will be required in order to prevent the decaying worms causing a pneumonia. If your birds have suffered from a parasitic disease, check whether the parasite in question has an intermediate host, if it does then this may need to be irradiated in order to prevent further cases. Furthermore the floor of the aviary may be contaminated, advice should be sought on the appropriate control. Panacur (fenbendazole) wormer should not be used whilst a bird is moulting. Generally speaking the author would recommend the use of Ivermec (Ivermectin) for the treatment of most round worm infestations, although it is best to take specific advice when one is aware what one is dealing with.There are at least two ascarids Capillaria & Serratospiculum which are not killed by ivomec, in these situations special dosage protocols should be used.

Coccidia :-it is not long ago that the pathogenicity (ie disease causing ability) of coccidia in raptors was uncertain. Merlins have always been most susceptible, but in the 1993 breeding season not only has the position in Merlins been much worse that usual, but the disease has caused an increased number of problems in other species. The exact reason for this is uncertain. Previously the coccidia which occasionally concerned us was Eimeria. More recently a different coccidia Caryospora neofalconis, has been responsible for almost all cases. In all previous research the parasite was thought to require an intermediate host. As it has characteristically affected young merlins from 28-40 days of age, and will have been in their bodies for some time prior to the onset of clinical signs, in order to complete it's growth cycle, this seems uncertain. The organism is also different to Eimeria as it does not simply live in the gut, instead it enters the body affecting internal organs such as the liver. In view of this treatment is on occasions more difficult. Clinical signs are of weight loss, inappetance, blood in the mutes, lethargy and general illness. Not all the signs will be present in each case. The disease most commonly affects young birds or very debilitated birds. Recently the fight against coccidia has been greatly assisted by the licensing of


'Appertex' in the UK. This drug is available in tablet form, only one dose is required, and it is effective against Caryospora & Eimeria spp.

Nutritional Disease :- as discussed under nutritional disease continues to be a major problem, with a greatly increased incidence during the 1993 season. The single commonest nutritional problem is a low blood calcium level in developing chicks, leading to deformation of the legs. This may arise for several reasons. Firstly an egg may be laid which is deficient in calcium, this seems bizarre , when he bird has mobilised enough calcium for the shell, but failed to put enough calcium in the yolk itself. The situation is seen more commonly in females laying in excess of one clutch. Chicks may be born with grossly distended growth plates in their long bones (ie near each joint), or with a depression or curvature in the keel. This situation is seen most frequently when either the hen or the chick is suffering from a kidney disease. If the kidney is affected although enough calcium is absorbed from the gut, it is immediately lost via the kidney the nett result is calcium deficiency.

The commonest cause of hypo-calcaemia is a low Calcium : Phosphorus ratio in the diet, in simple terms not enough bone. The aim should always be for the chick to receive a whole carcass rather than part of it. For young birds, being fed by the parents, supplying whole rabbits, quail, pigeon etc is not sufficient as you cannot rely on the parents to break up bone for the youngsters. Day old chicks are by no means ideal, but they are far better than meat alone. A better solution is whole mice or small rats. For hand reared chicks the whole carcass minus fur, feather and guts should be fed minced.

Thirdly the diet may be adequate, and the kidneys functioning well, but if the birds are kept either inside, or in a covered aviary (even if light is given by perspex lights in the roof), then the bird will be unable to convert the vitamin D which it has received in it's diet into activated vitamin D3 which is essential for correct calcium metabolism. Recent studies have shown that birds require as little as 45 minutes direct daylight daily for D3 synthesis.

A number of other vitamin and mineral deficiencies can occur, the commonest two which are regularly seen are due firstly to a deficiency of Riboflavin, one of the B vitamins, which results in a backward arching of the head, so that the chick is starring at the ceiling. Secondly is Vitamin E / Selenium deficiency which results in a medial (inward) rotation of the feet and a splaying of the legs, this is a separate condition to that seen in splay legs due to a friction-free nest substrate. Both conditions respond almost immediately to the correct vitamin administration.Casting should not be offered to young chicks, merlins in particular seem incapable of casting hard fibre, (especially rodent fur), until they are at least 18 days old.

Full Examination of the Injured Bird.

Examination of an injured bird is really not difficult, the more methodical, careful and experienced one is the easier it becomes. For most rehabilitators and falconers it is simply a question of discovering, is the bird injured, if so where, how serious is it. Will it respond to basic nursing care, if not how urgently must it be seen by a vet.

As previously discussed we have already made a very brief examination of this bird and then administered fluid therapy, (i.e.. shock treatment), and left it for two hours in a warm dark and quiet situation.

On re-examination again we must asses initially how much stress and harm are we going to cause, and how much benefit is going to be achieved. When considering this the species one is dealing with must be taken into account, i.e.. a wild peregrine or kestrel which lies on it's side or it's back is extremely ill, weak, or shocked and may not stand too much handling, where as a red kite or buzzard would be expected to behave like this.

If the bird is more lethargic than one would expect, then further fluid therapy, nutrition and antibiotics should be given.

As long as the bird is doing as expected then the full examination can then take place. If the bird is loose in the box, it may well now be considerably more lively.

Do not stress it by chasing it around the box or room in an attempt to catch it. Place a large towel over the top of the box, pull back each flap of the box lid one at a time, (preventing the bird from escaping by careful placing of the towel). Now with an open box, with the towel draped over the top, allow the towel to fall down on top of the bird.

It should be possible to make out the position of the birds shoulders by the movements of the towel, these should be grasped firmly. Allow the bird to grasp the towel, in order to prevent it from grasping you or it's own feet.

A proper examination can be carried out by one person, although it is much easier if you have an assistant to hold the bird, whilst you examine each part.

The examination should start with head, check the cere including the nares (nostrils), the top and bottom beak, inside the mouth, checking for wounds, white plaques (indicative of Capillaria, Candida or Trichomonas [frounce]), or swellings. Check that the eyes look normal, and when compared with each other they appear to be a pair.

Asses the rate and depth of breathing, as well as any abnormal noises which are apparent. If would be preferable to do this prior to handling or upsetting the bird, unfortunately in this situation this is impossible. The


bird’s distress may exacerbate any problem and make it easier to appreciate. Any bird with serious respiratory distress, should be returned to the box immediately and taken to an experienced vet for an accurate diagnosis to be made.(See later for diagnosis of respiratory disease).

At all stages of an examination it is useful to compare each of a pair, (i.e.. both eyes, wing tips, feet etc.), it is frequently easier to appreciate an abnormality when comparing a normal limb with one which may not be.

Check the external orifice of the ear, and ensure that the head and neck are held in a normal position. Next the bird is cast on it's back, initially the sternum (chest) is felt and the birds condition assessed

according to the degree of muscle covering. If the bird is fit or fat this will indicate that the injury is recent and the bird has been picked up soon after the initial accident. If the birds condition is low, then thought must be given to the cause, is it due to the injury, starvation since injury, or is there some other concurrent cause of loss of condition, such as a parasitic infestation.

Having assessed the chest, each foot is compared and examined, and then each leg in turn. The leg being examined should be extended (pulled down) from the body, and one's fingers should start right up at the hip joint. Place your finger over the hip joint then flex and extend the leg twice. If a grating feeling is felt there is a dislocation of fracture near the joint, and veterinary care should be sought.

Then move your fingers down slowly to the knee (stifle joint), feeling the length of the femur (thigh bone), on route. Repeat the bending of the knee joint, then move down to the hock (intertarsal joint), checking the tibio-tarsal bone on route.

From the hock check the metatarsal bone and ankle (meta-tarsophalangeal joint) (See previous diagram of skeleton).

Having assessed the legs and feet, return them to the restraining hands of your assistant, and move onto the wings, handle each in turn, again starting at the top and moving methodically down to the wing tip. Whilst doing so asses the feather condition, as this can give a lot of information as to the birds likely history.

Whilst the bird is still cast on it's back, check the vent and area surrounding it for signs of egg binding, soiling, blood loss etc..

Having made this further detailed examination, now consider the bird in relation to the flow chart of treatment which was shown before. A decision must be made as to whether further nursing, veterinary treatment (medical or surgical) or euthanasia is indicated.

Diagnosis of Respiratory Disease.Respiratory disease is perhaps one of the most complicated and important areas of diagnosis and

treatment in avian medicine. A bird with a respiratory condition may have a disease of the upper (i.e.. nares, sinuses, and conjunctiva or lower respiratory tract (trachea, lung or air sacs).

Infections of the lower respiratory tract are more serious, and may be caused by parasites (e.g. lung worm Syngamus trachea, or air sac worm Serratospiculum. spp). Infection may also be caused by bacterial infection, this may arise in particular after a bird has been immersed in water, after force feeding (if some food or fluid has gone down the trachea) or as a result of a 'chill' or other form of stress. Alternatively infection may be due to aspergillous (mould) infection.

The only way of sorting out this 'can of worms' would have been to start off with a methodical rational approach. The latter respiratory infection require experienced specialist treatment. If one imagines a scenario, in which a bird is suffering from a respiratory condition. The owner treats the bird with an antibiotic and a wormer, in case it has a parasitic condition. However despite the treatment the condition progresses. One needs now to change the therapy, but what to. Is this bird suffering from a bacterial infection, which was not sensitive to the antibiotic which was used. Or was the bird indeed suffering from a parasitic infection, if so one would expect the signs to continue, as a result of the now dead worms which are sitting in the wind pipe or air sacs rotting away. Or alternatively has the bird in fact got aspergillosis.

The recommended diagnostic work up would normally involve testing the faeces (mutes), for the presence of parasitic eggs prior to treatment, secondly taking a swab from the wind pipe in order to test for bacterial infections, thirdly a blood sample might well be taken to check for infection and perhaps the presence of aspergillosis. These tests could only have been carried out at the beginning, because as soon as treatment has been started the goal posts move.

Fitting, Central and Peripheral Nerve Defects.Fits and abnormal nerve defects are not uncommon both in captive trained birds but also in wild injured

birds. Fits are potentially fatal, and hence must be treated seriously.The commonest causes of fitting are:-

Hypoglycaemia (Glucose Defic.) (esp small spp) Hepatopathy (usually post virus liver damage)->Hypoglycaemia


Hyperglycaemia (Glucose excess),(esp Goshawks, stress induced diabetes).Hypocalcaemia (Calcium Defic.)(esp goshawks or if in lay)Lead Poisoning (and other poisonings)Vitamin B (Thiamine) Defic.(esp Harris Hawks)Virus (paramyx) Infections (usually post feeding pigeon)Bacterial Infections (ie meningitis) Trauma to the head (esp short wings, particularly spars)

Hypoglycaemia (glucose Def.) :- this is most commonly seen in sparrow hawks and other small species, which are being trained and flown for falconry. The condition occurs as the birds are being flown at too light a condition, or have simply been flown harder then usual, perhaps into a head wind, on a cold or blustery day. The same condition can be seen in any wild bird, which has been caught up or injured such that it has been unable to feed for a period of time.

Hepatopathy:-The same condition has also been seen in birds who are suffering from severe liver disorders, who for this reason are unable to mobilise glycogen into glucose for use by the body. This is most commonly seen in captive falconers birds, but of species which you would not normally expect to suffer from hypoglycaemia. Treatment of this more complicated form must be carried out by a veterinary surgeon, although the initial dosing with glucose by mouth is still indicated.Treatment; in the first aid kit is a container of glucose, you should also have a container of fresh water (which you fill before any days flying). Mix the minimum amount of water into the powder in order to dissolve the latter, the give 5ml per Kg body weight of the solution (the exact amount is not important) by crop tube. If you are single handed and cannot yet manage the crop tube then simply dribble the solution into the mouth. Once you have done this place the bird in a darkened box or carrier, and leave it well alone for 15 minutes, then give it a small piece of meat soaked in glucose solution.

Hyperglycaemia (diabetes) is not uncommon particularly in goshawks, at and around the time of manning. Such fits are similar to those of hypocalcaemia or paramyxovirus, and can only be differentiated on blood test. If one has a fitting bird, and should try and find a vet with 'in house' laboratory facilities, so that an immediate diagnosis can be made. Care in the interpretation of test results is necessary, as fitting itself will lead to an increased blood glucose level. Treatment is by intramuscular or intravenous injections of valium, and very careful insulin therapy if necessary. As such fits are stress induced they will invariably occur at the time of handling or feeding the bird. So long as the fits can be controlled, and the bird is not allowed to become too weakened, then they should return to normal within 7-10 days.

Hypocalcaemia (Calcium Deficiency):- this is one of the suddenest and perhaps most unexpected of fits in raptors. It may be seen in chicks, who are being fed on a deficient diet. As stated previously the diet fed, even to young chicks (with the exception of casting), should be as near to a whole carcass as possible. Some people rearing young birds seem to believe that only the meat needs to be fed, or even that quail, pigeon or rabbit steaklets are a better diet than day old chicks. Although we know day old chicks alone are a marginal diet and that these 'steaklets' may look better, the all important calcium : phosphorus ratio is stacked very much in favour of phosphorus, (which is high in meat) with a virtually zero calcium level. There is no doubt that if a chick gets as far as fitting due to calcium deficiency, that by this stage the long bones of initially the legs and then the wings are almost bound to be affected, often beyond the point of return. Young birds with this condition are almost inevitably unable to stand up. If you have a supply of calcium, by all means give the bird some if you suspect this, but then allow a vet to take an x-ray of the whole bird to asses the overall skeletal condition. If it is bad euthanasia may well be indicated.

Hypocalcaemia is also seen as a progression from 'egg lethargy' i.e.. a female bird sitting quiet, often on the floor of an aviary, slightly fluffed up, at around the time when you would be expecting her to lay an egg. Egg laying females build up a special supply of bone in the medulla (centre) of the long bones of the legs, during the late autumn and winter, in readiness for egg laying. When egg laying is in process, this calcium should be mobilised into the blood, to be available for egg shell production. If the bird is suffering from kidney disease, has had insufficient exposure to ultra violet light (i.e. sunlight), or has been on a chronic low calcium diet, then this process may not work. Equally if there is prevailing bad or particularly cold weather at that time then the bird may go into 'egg lethargy' leading to egg binding and or egg peritonitis. Treatment of this form consists of catching the bird up very carefully (so as not to break the egg in her oviduct), and taking the bird inside into the warm.

Often simply placing her in a closed box, with a heated pad under it, and placed beside a radiator, for an hour will relieve the situation. If not then a call to your vet is required, he or she will treat the bird with intravenous calcium, as below, plus the hormone oxytocin (0.3-0.5ml per Kg body weight)or better still PGE gel. Again the bird is placed in the hot box. If the egg is not forth coming then surgical intervention may be required from your vet. Antibiotics are usually indicated following such an episode as egg peritonitis is a common sequel. Furthermore the bird should be placed on a calcium and vitamin D3 supplement (see conditions of chicks), in order to try and prevent a reoccurrence with subsequent eggs of that clutch.

Hypocalcaemia is also seen in a number of the more excitable species, such as the goshawk, at any times in which they are particularly stressed. This is seen especially when goshawks are being 'manned'. It is thought by the author that the same cause may be responsible for the death of goshawks during transport. It is a sensible precaution to place a goshawk on a calcium and D3 (e.g. Nutrobal Vetark) supplement prior to any such stressful episode.


In any of these situations the fits start suddenly, and are relatively violent, they can lead to death in a very short period.

Treatment :- Consists of 1-5ml of 10% calcium given slowly intra venously. If this is not possible it may be given subcutaneously, although due to the negative effect on heart muscle, and hence circulation, s/c fluid is poorly and slowly absorbed.

Lead Poisoning:- still sadly occurs as a number of falconers continue to feed shot rabbits or pigeons. Some keepers claim to check the meat first. As a surgeon, experienced at trying to remove lead shot form birds and animals on occasions, I can assure you that even after x-rays have been taken, so that one knows where the lead is, it can be amazingly difficult or even impossible to find. Other keepers rely on the bird casting the shot up. All I can say is that all such keepers end up at a vets eventually, even if it's only once in 25 years.

The signs seen can be variable, they usually start as weakness in wings and legs, leading to a combination of twitches, tremors, fits, convulsions and coma. Typically the bird is sitting back on its hocks, with its legs and feet rotated medially, with each foot grasping the other. The latter positioning is almost pathonomonic, and can only be confused with the young bird with calcium deficiency.

Treatment :- the condition is confirmed by a vet after taking an xray, and treatment consists initially of injecting the bird with calcium versonate or Ca edta (at 35mg/kg twice daily for 5-7 days by injection) or D penecillamine (55mg/kg by mouth).

At the same time a very small quantity of epsom salts is given to speed the passage of lead through the gut and the casting component of the diet should be increased dramatically in a hope that alternatively the bird will be able to cast the pellets, or alternatively gastric lavage under anaesthetic may be used. The bird should be re-xrayed after 3-4 days, and if the pellet still present it should be removed surgically.

Thiamine (Vitamin B Deficiency): Thiamine deficiency is well documented as causing 'opisthotonous' i.e.. a backward and upward arching of the head, ("star gazing') and fits. In fact this cause of fits is unusual. If this is the cause, treatment is by intramuscular injections of thiamine or combined vitamin B complex. There is a very rapid response to treatment, the bird usually being back to normal within 15 minutes.

In recent years a number of Harris Hawks were found to suffer from a fitting condition which responded to thiamine, however in these birds it seems likely that their problem was not a deficiency but some form of disorder affecting the metabolism or mobilisation of the vitamin. Such birds responded to treatment, but require indefinite continued therapy with up to 125 mg thiamine daily by mouth. If they were off the treatment for more than 2 days, the fits would start again.

Virus Infections: Newcastle's disease (paramyxovirus), has and can cause fitting in raptors. The disease is common in pigeons and poultry. Infection can occur by contact with wild birds or from food species (chicks, quail, turkeys, pigeons etc..).

Traditionally birds affected by the virus, suffered severe fits and other nervous signs, and rapidly died. More recently several more mild varieties of the virus have been circulating. One can not predict at the out set of an outbreak what the out come will be. In the UK now a days many birds show transient signs of fitting, paralysis, paresis which last for 1-2 weeks and then disappear. In other countries were more virulent forms of the virus are still prevalent, once a bird is infected there is no chance of recovery, moreover the infection is highly infectious, any raptor showing nervous signs should be isolated from all others.

Bacterial Infection :-Birds blood systems have the ability to pick up bacteria from one sight of infection and then to deposit it elsewhere in the body. In view of this do not hesitate to seek treatment for even small infected wounds such as cuts or bumblefoot. If treatment is delayed then infection may well spread, leading to abscess formation in either the brain itself or the vestibular apparatus (the balance organ). Any such treatment will involve antibiotics from your vet, following treatment, if nervous signs persist a blood sample is likely to be indicated in the hope that one can ascertain whether infection is still on going, or whether the signs are simply caused by the residual debris or scaring.

Goshawk Cramps:- Although many species may be affected by paralysis of the legs goshawks seem to suffer from a condition unique to themselves. Paralysis of the legs may be caused by a spinal condition, or an infection, tumour or other swelling pressing on the sciatic nerve after it leaves the spinal cord, before it reaches the legs. The area in which we are particularly interested is the bone around the spinal cord, the region of kidney and its surrounding area. Alternatively the condition may be caused by an immune reaction to a previous virus infection.

With goshawk cramps the bird is either found initially to have weak legs, or to be completely paralysed. The top of the bird is absolutely normal, eating, biting, flying etc. Although the condition has been recognised for many years the treatment has been traditionally ineffective. Following a number of cases seen at The Clockhouse Veterinary Hospital in recent years, it is now believed that the cause is known in many cases. We have now been able to clearly demonstrate that although these birds have no lead in their gut on x-ray, that in fact it is lead poisoning that they are suffering from.

Traumatic Injuries :- Perhaps the commonest form of nerve defect in injured wild birds will be caused by traumatic injuries. Such injuries are commonest amongst sparrow hawks and owls. The former as they chase small birds into large glass doors or windows, the latter as they often hunt by flying down a road. They are so intent on their prey that they are oblivious of the 10 Ton articulated lorry which is descending on them. Clinical signs will be varied. It should be remembered that nerve tissue is very fragile, it is easily damaged and either does not heal or takes a long time. Bruising of nerve tissue will typically lead to paralysis, which will often take at least


six weeks to heal. Treatment of nerve deficits should comprise glucocorticosteroids (e.g. dexamethasone) at 2-4 mg/kg, covering antibiotics, additional vitamin B (either by injection, or oral supplementation) and general nursing.

Head injuries and concussion have already been discussed. Fractures of the spine itself are not uncommon. These may be divided in simple terms into three groups. Firstly those affecting the neck, secondly those occurring between the chest and the pelvis and thirdly those arising beyond the pelvis in the tail region. Assessment and radiography of spinal cases by a veterinary surgeon is important, so that unnecessary suffering is not caused to hopeless cases, whilst individuals with some chance are given the best opportunity.

Those seen in the neck area are usually fatal at the time of the incident, even if not the prognosis is very poor. The bird will be able to move and use its head, but not its wings, body or legs.Those found in the middle site have traditionally also thought to be disastrous. However, in view of recent cases treated it appears that often confinement in a small area (some birds will tolerate being placed in a sling), suitable medical treatment, some of these cases will make a full recovery.

Injuries occurring at the post-pelvis site will normally present with tail paralysis, the legs are also sometimes affected. These cases usually make a full and uneventful recovery.

Injuries to the head which cause nerve defects are not uncommon, they often result in a bird holding it's head to one side, or at an angle. Such birds do often return eventually to normal function. However even more careful than usual assessment of viability in the wild must be made. Such birds although they can fly well may not descend on prey or onto a perch in a straight and accurate line, instead diving to one side, or behind their intended point. Such end result is not conducive to efficient prey catching in the wild.

Peripheral Nerve Defects :- as a consequence of trauma or infection a number of local nerve deficits may occur. Traumatic injuries include wire injuries or other severe blows to a wing, this can lead to an 'avulsion' of the brachial plexus, i.e. the whole nerve bundle which stimulates the wing. Sadly such cases are beyond repair, the whole wing hangs uselessly away from the birds side, it has no sensation of control in the wing. A similar partial wing paralysis can occur, characteristically following a fractured humerus. On occasions when this occurs the sharp bone ends can lacerate the radial nerve.

In a similar manner fractures of the femur or tibio-tarsus can cause damage to the nerves of the leg with the same end result. Individual toes may become paralysed frequently as a result of bumblefoot infection or laceration following squirrel or other bite wounds. A similar presentation can be seen when a toe is broken or dislocated. It is important that these conditions are differentiated, if no swelling is present one can be certain that whatever damage has occurred is historic, however if the toe or foot is swollen then xrays should be taken. Birds with mal-placement, weakness or paralysis of middle forward toe or hind toe cannot be released, as these are vital structures for efficient hunting.

Poisoning.

Poisoning is a cause of a considerable number of emergencies in both captive and wild raptors. A whole range of clinical signs may arise, these include haemorrhage, nervous signs (such as tremors, fits, convulsions and coma), vomiting and diarrhoea, muscular weakness as well as others.

The clinical signs presenting are usually non specific, and hence the initial treatment will normally simply involve general support and nursing, as has been previously discussed under the heading of shock treatment. The initial aim is to stabilise the patient, to prevent further ingestion or absorption of further poison, and then to identify the poison if possible, in order that specific antidotes may be used. If diagnosis is delayed and some general non-specific treatment is indicated, then apart from the fluid therapy, BCK Granules or Forgastrin plus a small dose of epsom salts can be administered. The former bind the toxin whilst the latter speeds it's passage through the gut. Below a number of common poisons their clinical signs and treatments are listed.

Lead is still the commonest of all poisons affecting captive raptors. Poisoning may occur when keepers feed game, pigeons or rabbits which have been shot with a shotgun. Many keepers mistakenly believe that if plenty of casting is given that the odd piece of lead does not matter. Alternatively rabbit, pigeon or game may be fed which has been killed by other means (e.g. ferreted or shot with a rifle), the animal having previously received a non-fatal shotgun wound.

Clinical signs are of green faeces, weakness of legs and drooping wings, tremors, inco-ordination, fits and coma. Characteristically the bird is seen sitting on its hocks grasping one foot in the other.

Treatment involves control of nervous signs with anti-convulsants, sedatives or anaesthetics, whilst blood levels are controlled using chelating agents such as Ca edta or D Penecillamine. Radiographs should be taken to confirm the diagnosis. Additional casting is fed, concurrent with chelation therapy, for a period of 3-5 days, alternatively the pellets may be removed by gastric lavage under anaesthetic. Radiographs should then be taken again to assess if the lead has been voided. If not then the pellets should be removed by endoscopy or surgery. It is very rare indeed for lead shot in a bird's body in sites other than the gut to cause poisoning. Hence if a bird is shot and the pellets are lodged in the body but not causing any problems, then they should be left alone.

Mercury poisoning is not common and is only likely to be seen in wild birds. Mercury is used commercially as an anti-fungal seed dressing agent. Any wild raptor taking a number of seed eating birds, which have fed on


this treated seed, may suffer from chronic toxicity. Clinical signs are of weight loss, lethargy, inco-ordination. Treatment is general nursing and chelation agents as above.

Warfarin and other anticoagulant rodenticides are an occasional cause of poisoning. Poisoning usually arises after a stupefied mouse or rat, having ingested poison staggers across the aviary floor. Clinical signs include haemorrhage or bruising under the skin, in the mouth or passing blood in the faeces (mutes). Treatment is symptomatic nursing, including fluid therapy, blood transfusions can be used, as well as Vitamin K which is the specific antidote. There is good evidence that some but not all birds are resistant to warfarin.

Alphachloralose is used to control feral birds (pigeons and sparrows) and rodents. It acts by slowing the metabolic process down. The victim then dies of hypothermia.

Clinical signs include inco-ordination, lethargy, stupor, and sleep. Treatment includes heat and fluid therapy.

Strychnine is perhaps the most rapid and dramatic of likely poisoning agents. Strychnine is used legally for the under-ground control of moles, but is also occasionally used illegally (usually by gamekeepers) to control jay, magpie, crow and fox. The poison is usually put down as baited eggs or carrion. The site of poisoning is often evident by a pile of corpses scattered around the position of the incident. Clinical signs are of tremors, fits and a characteristic backward arching of the spine. Treatment should involve milking out of any further meat that is in the crop. This is achieved by pressing finger and thumb together at the base of the crop and working upwards. The meat should then appear in the mouth and retrieved from there. Fluid therapy and anti-convulsants are necessary if one is to stand any chance of saving the bird. Sadly few birds or mammals survive this poison.

Botulism is an uncommon but potential serious poison. Botulinum toxin is produced by a bacterium which grows in stagnant water or decomposing food. It can arise particularly in a breeding aviary, where food and water may lie undisturbed for long periods of time. Signs are of a flaccid paralysis, i.e.. droopy wings and an inability to stand. Treatment is by general nursing and if possible the use of a specific antitoxin.

Carbon monoxide may be emitted from a gas fire with inefficient exhaust, from car exhaust or from paraffin heaters which are burning inefficiently. Birds collapse unconscious. On examination their mouths may appear redder than usual. Treatment is to immediately try and stimulate breathing, this is sometimes accomplished by moving the wings in a normal flight action. Alternatively, gentle but firm pressure on the chest may help. If the bird is alive, immediate treatment by a vet, with respiratory stimulants and oxygen is required.

Phenobarbitone is an injectable anaesthetic which is used in the euthanasia of domestic animals. Occasionally in error supplies of rats or mice, (supposedly excess to requirements), from laboratories, may include an injected carcass which had been placed in the wrong bin and hence enter the raptor food supply. Clinical signs are of a sleepy or anaesthetised bird, treatment is nursing, fluid therapy, stimulants all of which will require veterinary assistance.

Drugs may in certain species cause toxic effects. For example one anaesthetic 'Saffan' is safe in most raptors but will kill Red Tail Buzzards. Drugs should only ever be given to a bird after speaking to a vet who is experienced in this field.

Accommodation for Convalescing Birds.

As stated previously, there are serious legal implications in keeping birds in accommodation which is not sufficiently large for them to stretch their wings out properly, unless under the care of a vet or during transport.

When treating injured raptors, there is a whole range of different sized accommodation required at different stages of treatment. For example a bird with a fractured ulna but intact radius, may well be best treated by simply confining it to a small night quarter. However this is only legal when carried out under veterinary supervision. As time progresses the size of the accommodation will be increased to allow increased exercise.

As previously stated, the initial accommodation for an injured bird is likely to be small, dark and warm. Different birds with different ailments and species with different temperaments will require separate consideration.

With injured wild birds one prime concern is that generally speaking the bird should be kept as remote from human contact as possible. As with all golden rules there are of course exceptions.

A young bird (often even up to 60 days of age), should be prevented from even seeing humans if possible, in order that imprinting can be avoided. Puppet feeding and crèche or foster-rearing should be used.

For older birds, who may need to be trained in order that one can be sure that they are fit to kill, and hence survive back in the wild, may in fact benefit form some gradual humanisation, prior to manning and training.

When considering accommodation one should always consider the ease of cleaning the accommodation, the prevention of injury to the bird (e.g.. not able to cut his cere or head on the aviary roof) and the provision for proper observation. Heat will need to be given to all birds which are still in an acute phase of any illness or injury. Heat may be provided by heated pads or heat lamps. Whatever method is used be sure that the bird is adequately warmed but not cooked !

Housing

Once a bird has been stabilised and requires no extensive handling for medical treatment, it should be placed into a rehabilitation aviary. Materials available for building aviaries are numerous, in view of the limited budget of most rehabilitators cheap or second hand materials may often be successfully utilised. As long as the aviaries are safe and durable then this is acceptable. There are of course a number of other very important Page 41 Copyright Neil A Forbes FRCVS 1996

parameters which do need to be considered. Chain link fencing or similar can be used for the side walls of the aviary, although this should be plastic coated, as uncovered (ferrous) wire will tend to rust in time leading to an extremely rough and abrasive surface. It should also be coated on the inside with netlon, or other soft nylon netting. This acts not as an inner softer protective lining but more as a visual warning to the bird. With such a liner in use the bird will see it and turn before scalping itself on the wire mesh itself. Alternatively wooden doweling rods can be placed from the ground to the ceiling at suitable distances apart from each other (dependent on species and size). The aviary itself should also be designed with the most frequent rehabilitate species in mind. As stated previously it is important that convalescing birds are not startled or harassed by humans. It is often preferable to employ an adaptation of the sky-light seclusion aviary. The main adaptations on this successful design is that it is advantageous if the bird is able to get up high and look out from a suitable vantage point, without at the same time feeling threatened at all.

Doors

It is essential that a double safety door is used, equally it is sensible to make it large enough to get in and out comfortably, especially bearing in mind that one may be carrying an injured bird and a net at the same time.

Perches

It is important that the perches offered suit the individual occupant at that time. If the bird is at all handicapped in it's manoeuvrability then do not clutter up the centre of the aviary unduly. If it has difficulty gaining height, ensure that you have graduated perches, which act as a form of ladder, so that it can gain height by climbing rather than being forced to fly. The highest perch should be shielded in order to give security. Often it will help (especially with owls and young birds) to house a number of birds in the same aviary. This is good and helps with socialisation, as long as there is no inter species aggression. It is often a good idea to offer some from of cover for a bird (e.g.. male sparrow hawk), being chased by a larger (possibly female) bird to seek refuge in. Perches should vary in size and texture, as many as possible should receive regular sunlight, as this will help control residual bacterial contamination. Suitable perches should also be available under cover in order that birds are not compelled to sit in either a prevailing wind, or the rain.

Feeding

Needless to say a good varied diet is essential for a recuperating bird. Do not forget that such a bird will have a greater food requirement than a normal fit and healthy bird. Bare in mind that an injured wild bird will not be familiar with some readily available commercial food sources. So do not assume he is eating the chicks. It is often necessary to force feed injured wild birds for the first few days. Food should be introduced via a chute, or removable tray. The latter is a particularly good system as any uneaten food (unless cached) remains in the draw, and hence at the time of the next feed if less has been taken then the situation can be investigated. The latter may be indicative of either a sick/dead bird or simply that you are giving too much food. It is vital that the food is good quality, balanced and varied, and fresh. Needless to say it is imperative that the bird does not see the supplier of it's daily food. Once the food has entered the aviary it should not be situated in direct sun light as in summer months this will speed up putrefaction. A bathing/drinking bowl should be present, this is best filled by a hose pipe which hangs permanently over it, remotely controlled from outside.

Floor Material

Over the years many alternative floor coverings have been used, some good some not so good. Perhaps the ideal structure is an initial concrete floor set with an adequate fall so that it drains, (but not into an adjacent aviary). Over he top of this pea gravel is added. As mentioned previously plants can be advantageous, and these can take up temporary residence in large pots or other containers, sunk into the gravel. The advantages of this system are that the gravel can be washed, if necessary it can be removed and sterilised, it also drains well. The disadvantage is that it is expensive, and in direct sunlight the gravel can become extremely hot. Whatever is used it is important that it can be adequately cleaned, in case it is found retrospectively to have harboured a bird suffering from an infectious disease.

Siting of the AviaryPage 42 Copyright Neil A Forbes FRCVS 1996

When deciding on the site of an aviary, the following points should be considered:- Noise nuisance/PRIVACY to birds/humans

PROTECTION FROM THE WEATHER

SECURITY

DRAINAGE

Of all elements perhaps the most important is the provision of adequate observation holes, so that where ever the bird is in the aviary at any one time, that you will be able to visualise him and check that he is fit

and well. This point cannot be over emphasised.

Hygiene Control in the Rehabilitators FacilitiesWild injured raptors are very often infected with a whole range of organisms, these may comprise :-Parasites (endo - eg. worms, coccidia, or ecto- eg flat flies, lice etc)Bacteria (eg Salmonella spp. , Mycobacterium spp- which causes tuberculosis, Campylobacter spp etc.)Viruses (eg Paramyxovirus 1 - ie Newcastle Disease, Falcon Herpes virus, Avian Pox etc)MycoplasmaChlamydiosis

Food supplies for feeding to raptors may be contaminated eg Salmonella spp, E coli, collection, storage, preparation and feeding of food should be carefully controlled, as well as detailed attention to personal hygiene. Gloves, hoods, jessies etc should not be held or pulled with the mouth.

Infection may be introduced into the facility by feral birds, rodents, arthropods which are attracted to the site by the presence of surplus food. Such feral animals and birds should be controlled or discouraged.

Who may become infected : You the keeper, the wild injured birds, any resident birds, the wild life population following release.

Prevention : Quarantine - ideally new birds admitted should be kept in isolation for a period of 35 days, prior to mixing with any other birds. In reality most casualties are maintained in isolation anyway. However action must be taken to prevent passage of infection from one bird to another. Such transfer is most likely to occur as a consequence of passage on fomites (inanimate objects - such as gloves, clothing, shoes), or by contamination of the accommodation which fails to be adequately cleaned following the birds removal to alternative accommodation or release.Action : when birds first come in either keep them in disposable containers (eg cardboard boxes), or in containers with impervious walls, which can be readily and thoroughly cleaned prior to reoccupation. Many keepers rely on powerful disinfectants (eg F10, Virkon S or Hibiscrub). Although these are both powerful agents, they are only ever effective when used in the absence of organic material, i.e. the container must be cleaned before it can be sterilised, other wise the sterilisation will be ineffective.

One should have a through flow system, so that it is acknowledged that birds come in dirty and hopefully go out clean, new (dirty), birds do not mix with birds ready for release (clean). Approx. 65% of wild raptors will carry some form of parasitic burden. They have been living quite happily with these parasites for a period of time, without any ill effect. However once the bird becomes sick or injured, the parasite infestation may well gain the upper hand. It is better to assume that all incoming birds are infested and treat them accordingly, with a standard round worm therapy, eg Panacur or Ivomec. Although one appreciates that this does not cover all parasites, if the bird does not improve in clinical condition then one would advise that a faecal sample be tested by a veterinary surgeon.

The presence of ecto-parasites is usually just an indication of the birds poor condition, however these should be treated with a safe and effective treatment (eg Frontline Spray - available only from vets).

If a bird appears unwell, it's faeces (mutes) are abnormal, then the bird should be examined by a vet and the faeces tested for bacterial infections.

If any bird dies, it should be autopsied, although one appreciates that this is an additional expense for a dead bird, the reason for having this performed is so that one can be certain that the dead bird has not left a legacy of infection behind in your facility.


Some infections may not cause obvious illness in a bird until months or years after infection has occurred (eg tuberculosis), so maintaining a good record or all birds in, their ailments, which accommodation they were kept in, their treatment, identification and release is invaluable. All birds released should where ever possible be rung, so that post release survival rates can be monitored long-term.

Aviary Design : it is inevitable that at times over the years that your longer term or outside accommodation will become infected or contaminated. Your aviaries should be designed to facilitate a thorough clean on a regular basis. It is preferable if the floor of the aviary is concrete, or at least covered with a thick plastic sheet. Over the top of this one may place soil or gravel. In this way all the ground surface material may be removed periodically, washed, sterilise and replaced or renewed. If conversely the ground is a soil base, then you can never adequately clean it. Aviaries are better designed with a solid roof and one open side, so that feral birds flying over cannot contaminate the aviary. the aviary water supply should be protected from faecal contamination by wild birds. The bottoms of the aviary walls should also be solid to prevent arthropods gaining access to the aviary as these are often intermediate hosts for raptor parasites.

Dilemma's : there are occasion's when you may feel it is important to mix newly taken in casualties. In particular this is relevant with 'orphaned' birds, where the risk of spreading infection is less than the risk of imprinting.


Assessment of the Viability of the Injured Bird.There are three important aspects that should be considered before a bird is released. These are the

health and condition of the individual bird, its relationship with man, and the locality in which it is going to be released. We will consider each of these in turn.

In order for a bird to be considered fit for release it must have the physical ability to fly, see, grasp and kill prey adequately. The mental or psychological ability to happily and peacefully coexist with members of the same species.

Health of the Bird

Only approximately 30% of all rehabilitated birds survive following even the most carefully planned release process.

In view of this one must be particularly careful that the bird is as fit as possible in order to give it every possible chance.

There are certain key handicaps which mean that a bird should never be released:-Loss of any limbLoss of an eye/sightLoss of a hind talonPermanent loss of any part of the beak

Inability to waterproof the plumage

The above criteria are based on the necessity for a released wild bird to be able to fly, hunt, kill and eat in any weather. There are also a number of other points which all have to be assessed on an individual basis. For example if there is permanent loss of, or loss of function of any primaries or deck (tail) feathers, the bird may or may not be able to cope. There is no doubt that the bird will have to be able to hunt and kill. The effect of the handicap must be assessed either following traditional falconry training and flight, or in a wind tunnel. Some species such as the buzzard, who feed predominantly on carrion, do not require great acrobatic skills. Short wings (sparrowhawk, goshawk etc) require greater flying abilities, but kill from an observation position, by waiting for prey and making a short flight. Conversely the falcons do require almost perfect flight for high-speed chases, in order to kill and survive. So not only does the injury need to be assessed but also an estimation of what effect this deficit will have on the birds ability.

The bird must be fit in feather and posture. Although a fractured humerus may have mended, is there any residual droop or twist to the wing.

To quote the old cliché 'the proof of the pudding is in the eating' with reference to this situation of the proof of recovery is in the ability to catch and kill quarry. It is for this reason that it is very much part of a rehabilitators function to retrain a bird to fly and kill, prior to release, where ever possible.

Any bird must be free of parasites and diseases at the time of release.If it is decided that the bird is not fit for release, what then ? There are very many different schools of

thought on this subject. The authors opinion is that unless the bird is extremely rare, (eagles, red kite, merlin, harrier) then an invalid (ex wild) bird should not be confined in an aviary simply so that it can be used for breeding. If this is its only possible function then the correct answer almost certainly is for the bird to be put down.

Assessment of Eye SightAs mentioned above normal eyesight is essential for release to the wild, however the accurate assessment of functional eyesight is not easy. Previous studies have shown that many injured raptors & owls suffer from defective vision. The cause of such a handicap is varied, either the bird suffered detachment of the retina, ocular haemorrhage or cere damage at the time of the injury, or possibly it had the injury because it's eyesight was already impaired. Many birds which are admitted to a rehabilitation centre in a thin starving state may in fact be like this because of ocular defects preventing them from catching prey efficiently. Birds with defective vision will appear outwardly normal, as the site of the defect is most frequently the retina. The retina is the sensitive part of the eye which detects light, colour movement and is situated right at the back of the globe of the eye, (ie in the middle of the head). Although 30% of all trauma cases have posterior chamber haemorrhage, some retinal damage may have been present previously as a consequence of Toxplasma infection. Toxoplasma is a protozoal parasite the intermediate host of which is rodents, and hence there is a natural route of infection for most wild raptors simply by eating wild infected rodents. The latter damage is often permanent and irreversible. The patient's retina is totally invisible to the rehabilitators, in fact most veterinary surgeons will find it difficult if not impossible to examine thoroughly. However if you are in any doubt you certainly should request your vet to examine the bird, despite a few differences there is little difference between a cats eye and a birds eye, and hence if there is any significant defect your vet should be able to detect this. Whether a vet examines the bird or nor, prior to release the bird's behaviour in the aviary must be carefully assessed, ensure that the bird appears to see well on both sides, and reacts normally to movements in all areas of the aviary.


Relationship with ManImprinting can occur very easily, at best it is an embarrassment, at worse simply dangerous. An imprinted

bird is unlikely to breed in the wild, but may well occupy a nest site, thereby depriving a further potentially fertile pair from using it. A complete imprint may look for and even attack (fly at) a human, in the hope of finding a suitable mate. This is particularly dangerous with the larger species such as buzzards, goshawks and eagles. Any imprinted bird must not be released and every step should be taken to prevent imprinting from occurring in the first place.

Not only may a bird become imprinted upon man, but also on an unsuitable prey/food, species or habitat. It is not easy for an artificially reared merlin to find day old chicks in the middle of a grouse moor in Scotland. Likewise it would not help a released Golden Eagle if it was used to flying and being fed in a suburb of London. Apart from it's relationship with man the bird must also recognise it's own species, rather than being attracted to members of different species

Rehabilitation Techniques

The Site for Release

The site encompasses not only the geographical position, but also the vegetation type, prey species availability, weather and time of year. Great controversy has been caused by the multitude of unsuccessful barn owl releases. Very often these have not been adequately planned. A suitable site for a barn owl must be more than three miles from any major trunk road, have a considerable area of permanent pasture and in the latter a large population of short-tailed field voles. Releasing invalid birds in less than optimum sites, not only leads to their demise, a waste of your time, but could also lead to a charge under the 'Abandonment of Animals Act 1979'.

With respect to weather, it is important that birds are not released in any extremes of weather, either droughts or storms. It is well worthwhile checking the long-term forecast before actually releasing a bird.

As far as time of year is concerned, this applies particularly to migratory birds such as the 'hobby', which migrates to Africa each autumn. Any hobby would need to be released at least 3-4 weeks prior to likely migration times in order to build up sufficient fitness before departureFor any species, both suitable nest sites and a readily available supply of the natural food species must be available.

Habitat Assessment

The area which is chosen for release must be natural terrain for that species. It is also advisable to consider other avian species which may already inhabit this area. Species which one should be particularly aware of are rooks, crows, magpies, as well as woodpeckers, tits and some other song birds. Such species will tend to constantly mob the released bird. As a result the bird will be kept constantly on the move, allowing little time to rest or hunt, in the mean while burning up precious energy by staying on the wing for long periods.

Food availability is all-important, as previously stated it is preferable for the bird to be trained and seen to kill proficiently prior to release. However in the period immediately after release, food should be made available for the bird so that its wild-caught dinner can be augmented.

There is also a danger for the prolific rehabilitator of over saturating what was initially a good release site.Ordinance survey maps and BTO (and other) references of established breeding pairs may be useful, in

order that a given species is released within it's normal population range, in a suitable habitat, but importantly not too close to others of the same species. The territory size of given pairs will vary depending on the food availability. Generally speaking the better the food supply, the smaller a territory each pair needs. Their food supply needs to be not only sufficient to survive but also hopefully enough to successfully rear a clutch of young.

Timing of Release

The longer a bird is kept in captivity, the more troublesome the release is likely to become. If a bird is fit for release within 14 days of the initial injury, then it should go back to it's initial territory. If however release has been delayed, then the bird is usually better released in another area.

As previously stated weather and ambient temperatures should be considered. Winter is not an easy time of year to release birds, as their metabolic rates will be higher, (on account of the cold weather), and hence food requirements greater. During winter the quarry base tends to be lower with few insects, small mammals and reptiles available.

The summer months are ideal for release, the days are long, the breeding season is over and food is more plentiful.


For non migratory species the autumn can also be good, as ground cover is diminishing, making hunting easier, whilst quarry is still relatively plentiful.

Time of day is also important for a release, diurnal birds should be released early in the day whilst owls should be released shortly before sunset.

Methods of Release

Each method has it's own inherent advantages and disadvantages, each has it's place and different ones will be most suitable on different occasions. Release subjects can be divided into one of three categories:-a. Adult birds. Experienced hunters. 4-6 weeks hospitalisation. Good condition. b. Adult birds. Experienced hunters. >8 weeks in captivity. Fair condition.c. Young birds. Inexperienced at flying and hunting. <6 weeks in captivity. Good condition.

As birds regain fitness, intra-abdominal fat is utilised and muscle tone through out the body is developed, and strengthened. Manoeuvrability and stamina will increase daily, as long as the bird is given the opportunity to fly.

Variations of the traditional hack and falconry techniques are often appropriate and adequate. Birds can be flown to the fist or the lure to achieve this fitness. Were possible this fitness training should be carried out in the area into which they are to be released.

The falconer's definition of 'hack' is a period of liberty offered to a young inexperienced bird to enable it to naturally develop the necessary skills required in flying and hunting. In our situation the young inexperienced bird' is replaced by the 'convalescent bird'. There are several techniques used. A few of them will be discussed briefly below.

A Feeding Board or Hack Board

A platform is secured in a tree or other secure site, which offers the bird a good view of the surrounding countryside. Food is secured to the hack board. The bird is carried on the fist, unhooded to the hack board. This is done to familiarise the bird with it's new surroundings. The bird is then tethered to the board and allowed to feed. Initially the hawk is only left on the board for 10 minutes, after the end of feeding. This is repeated daily until the bird attempts to fly to the board as you approach it in order to reach it's food. During this process the bird is only offered food on the board.

It is worthwhile observing the birds posture whilst on the hack board. Initially he will crouch or lie down if mobbed by other birds or if other raptors are in the area. However as his confidence increases, he will stand prominently and defiantly irrespective of who else is in the vicinity.

The day you decide to release the bird, only give him half the normal food. As he is still hungry he is more likely to remain in the vicinity of the hack board. The rehabilitator will also now have to cut off the birds jessies. This negative stimulus will help break the falconer : patient bond.From then on food is continually placed out on the board and tied to it, at a regular time each day. One should continue to leave food out for a considerable period after the bird is last seen.

Hack Flight

The principle involved here is similar to that previously mentioned, except that it involves far less human contact. The technique makes use of a hack aviary rather than a platform. Hack flights are usually simple aviaries, built along similar lines to the previously mentioned recuperation aviary. They are however best kept simple and preferably collapsible and transportable so that different hack sites may be utilised.

Food is tied in a similar fashion to a platform inside the flight. When the birds are feeding well the flight is opened, to allow the birds to venture out and investigate the surrounding countryside. Again the birds must be kept fairly hungry in order to discourage them from departing, before they are fully fit and ready. Birds released in this way do not acquire the same degree of territoriality as those hacked using the platform. For this reason they must not be frightened or disturbed during the delicate procedure.

There is no point in struggling to put a bird back together after an injury and get it fit, if the 'hacking' process is not adequately planned and carried out.

It is hoped that all participants have found this day's lectures informative and useful. It is anticipated that both this and other lectures on birds of prey will be available in other areas of the United Kingdom. If you have friends or colleagues who you feel would benefit from this type of information, please ask them to contact the main lecturer at the address as shown on the front cover.

Acquisition of a New BirdAt the time of writing many falconers have planned the purchase and collection of new birds, hopefully all is planned and the arrival of the new bird can be made as easy and straight forward as possible, but what factors should we have planned or considered. A simple check list is given below.

Choice of bird - suitability for prospective owner in respect of:-Page 47 Copyright Neil A Forbes FRCVS 1996

accommodation availability, a block is no replacement for an aviaryexperienceuse, hunting (availability of suitable ground)breeding - physical and mental compatibility with prospective matespecies and individual resistance to disease (eg. Gyr falcon poor resistance to Aspergillosis)CostSource - from a reliable breeder only, who will provide a pedigree indicating minimal or

no inbreeding.First clutch birds are generally a better quality than subsequent birds.

Preparation - join a local club if you are not already a memberlocate an experienced (preferably local veterinary surgeon) - seek references through

a local club if necessary.food, furniture, telemetry (if relevant).clean, safe, secure, ventilated travelling box for collection of the bird.time - ensure that you will have enough time available to spend caring for the new

bird, if necessary plan leave from workplan pick up date, ensure the bird has not been fed during the 12 hours before the journey home and has had no casting for 24 hours, or has already cast.check weather conditions for travelling avoid the heat of the day, if summer time.

Collection of the bird - check the birds condition and paper work before paying or leaving the breeder.

Seek agreement with the breeder that if subsequent to the bird being checked by a suitably experienced falconer or vet, the bird is found to be unsuitable for the purposes for which you are to buy it, that you may return the bird for a full refund, so long as it is returned within 72 hours, and in the same condition in which it initially left the breeder. This agreement should be in writing.

Travelling - ensure the bird is not too hot, or exposed to any fumes during transport.

Arriving home - take the bird from the box, and depending on the state of training allow it to settle somewhere quiet and dark, or release into an aviary.

Quarantine - the new bird should be kept separate from (in all respects), any already resident birds for a period of at least 14 days, in case it is incubating any infectious disease.

Examination of the bird - preferably use the services of an experienced veterinary surgeon, to carry out a full physical examination of all new birds. A faecal examination should be carried out, and preferably a blood sample as well, in order to detect any sub-clinical disease that may be present.

Identification - all birds purchased should have a closed or cable tie ring on them, it is advisable to also have an electronic microchip implanted by your vet, in case the bird is ever stolen and the ring removed.

Tethering - do not tether young birds, until their bones are fully hardened. When birds are first tethered keep the leash length to the absolute minimum, just sufficient to allow the bird to get down from the perch and back up again. Whilst tethered the bird should be protected from predators, (two as well as four legged), the weather (hot, cold, wind and rain). Wherever possible once a bird is trained it should be flown direct from an aviary rather than being kept tethered.

Training - should be carried out a s slowly and in as stress free manner, as possible for the sake of the bird. If a bird is stressed, it will be more likely to succumb to infection.

Parasites - all birds should be routinely checked for parasites (by having a mute test performed), at the end of the hunting season, and again before taking the bird up at the end of the moult. A current survey of routine monthly faecal examination of captive merlins, indicates that between 30 - 40 % of captive merlins are carrying a parasitic burden. Although a parasitic infestation may not in itself be causing a problem to a healthy bird, if that bird suffers any kind of accident or other illness, the parasitic infestation may then become life threatening, and hence any parasitic infection should be treated.

We would like to wish you and your birds Safe Falconry and Successful Rehabilitation.


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