A Basic Approach to Poultry Disease Diagnosis
Mohamed El-GazzarDVM, MAM, PhD, DACPV
Assistant Professor Poultry Extension Veterinarian
The Ohio State University
Trends in Food Production
• Organic
• Free Range
• Produce local/Eat local
• Shift in Poultry Population
Urban Chicken Ownership in Four U.S. Cities
• Denver• Los Angles• Miami• New York
– Around 1% of all households– Quadruple (4%) within 5 years– Not enough veterinary services
Backyard flocks Not only Urban
• Urban, Suburban and Rural• Few birds to several hundreds (Average 49
birds)• Still food animals not Pets• Population medicine • Mainly Chicken• Some Turkey• Other species
But they are falling through the crakes!!
• Wall Street Journal http://online.wsj.com/news/articles/SB10001424127887323527004579081812563033586
• A gap that needs to be filled
• Small and mixed Animal Practices or Even Poultry Specialists
Poultry Disease Diagnosis and Control
• Clinical History• Clinical signs• Necropsy• Laboratory diagnosis• Control
Rule Out List
• Clinical signs grouping– Respiratory– Digestive – Musculoskeletal– Neurological – Others
• Samples to collect• General control
Poultry Disease Diagnosis
Necropsy
• Extremely useful in poultry • Recently dead • Clear clinical picture• Sample collection
http://partnersah.vet.cornell.edu/veterinarians/avian-necropsy-examination
Usual Clinical Samples
• Blood serology• Swabs bacterial isolation• Organs virus isolation• Organs histopathology
Disclaimer
• Non of lists is comprehensive
• Only most common
• Starting point
Respiratory Diseases
General signs:• Mortality• Anorexia/Fever/lethargy• Coughing/Sneezing• Rales/Weezing• Nasal/Occular discharges• Swollen head/swollen sinuses• inflamed eyelids
Respiratory Diseases
Gross lesions:• Inflammation of:
– head tissues– nasal cavity– conjunctivitis
• Tracheitis• Pneumonia • Air sacculitis• Polyserositis
Turbinate
Normal Trachea
Inflamed Trachea
Early Airsacculitis
PolyserositisPnuemonia
Respiratory DiseasesRule out list:• Newcastle disease• Infectious bronchitis• Infectious laryngotracheitis• Avian Influenza• Mycoplasmosis (4 species)• Colibacillosis (E. coli)• Fowl Cholera (Pasteurella multocida)• Infectious coryza (Avibacterium paragallinarum)• Turkey coryza (Bordetella avium)• Aspergillosis• Cryptosporidiosis• Gape worms (Syngamus trachea)
Respiratory Sampling
Samples:• Blood Serology• Eye lids, Trachea, lungs and
kidney Histopath• Eye lids, Trachea, lungs and
kidney Virus isolation• Trachea/choana/airsacs
swabing Bacterial isolation
Digestive Diseases
General signs:• Mortality• Anorexia/Fever/lethargy• Dehydration • Diarrhea/Loose droppings
(watery/bloody)• Pasty vent/wet litter
Normal Droppings
Loose Droppings
Digestive Diseases
Gross lesions:• Intestinal mucosa• Intestinal content• Parasite• Pathognomonic
lesions
Digestive DiseasesRule out List:• Hemorrhagic Enteritis Virus• Turkey Corona Virus • Clostridium species• Salmonella species• Coccidia species• Histomonas meliagridis (Black head)• Trichomonus gallinae• Intestinal helminthes (Tapeworms and
Round worms)
Digestive Diseases Sampling
Samples:• Intestine/liver/other
histopathology• Intestinal/liver/spleen swabs bacterial isolation
• Intestinal scrapings• Impression smears
Coccidosis• Most common protozoan
parasite• Mortality/economic losses• Bloody Diarrhea E. tenella• Diarrhea (not always bloody)• Predispose for Clostridium
enteritis• Vaccines• Amprolium for prevention and
control
Eimeria acervulina
Eimeria maxima
Not All Internal Parasites are Intestinal
• Histomonus meliagridis(Black head)– Liver lesions – Cecal cores
• Syngamus trachea (Tracheal worms or Gapeworms)
Histomonus meliagridis
Syngamus trachea
External Parasites• Lice• Mites
– Red mites– Northern fowl mites– Scaly leg mite
• Powdering, dusting or spraying of insecticides– Birds and Environment– Minimum of Two treatments– 7 days interval
Red Mites Northern fowl Mites
Chicken Lice
Musculoskeletal Diseases
General Signs:• Mortality• Paralysis• Lameness• Down birds
Musculoskeletal Diseases
Gross Lesions:• Nerve inflammation • Joint inflammation• Foot pad infection
(bumblefoot)• Weak/soft bones
(rickets or osteoporosis)
• Bone deformities
Musculoskeletal Diseases
Rule out list:• Marek’s disease (nerve involvement)• Reo virus • Staphylococcus aureus• E. coli• Pasteurella maltocida• Mycoplasma synoviea• Calcium/Phosphorus deficiency• Ionophore toxicity• Genetic deformities
Musculoskeletal Diseases
Samples:• Swab lesions bacterial isolation• Nerve/muscle/affected tissue histopathology• Feed samples feed analysis
Neurological Diseases
General signs:• Paralysis • Ataxia • Torticollis• Tremors
Neurological Diseases
Rule out List:• Marek’s Disease• Avian Encephalomylitis• Newcastle Disease• Influenza• Pasteurella• E. coli • Nutritional deficiency• Ionophore toxicity
Neurological Diseases SamplingSamples:• Nerves/brain histopathology
• Lesions other organs histopathology
• Organs virus isolation
• Blood serology
• Feed feed analysis
Vitamin E difficiency
General signs:• 3 forms of the disease
– Encepahlomalacia– Exudative diathesis – Muscular dystrophy
Exudative diathesis
Muscular dystrophy
Other Common Conditions in Backyard Flocks
Egg Production problemsBirds are not laying??• Review lighting• Review feeding• Water consumption• Infectious causes
– Egg peritonitis– New castle– Infectious bronchitis– Laryngotracheitis– Influenza – Egg drop syndrome– Pasteurella– Coriza– Mycotoxins in feed
Egg peritonitis
Pox virus
• Dry form and wet form• Collect samples for histopathology
Dry form Wet form Inclusion bodies
Tumor Viruses (3 viruses)
1- Marek’s Disease2- Leukosis/Sarcoma3- Reticuloendotheliosis
Recommended References
• Avian Disease Manual: 7th edition 2013
• A laboratory Manual for the Isolation, Identification and Characterization of Avian Pathogens: 5th edition 2008
• Diseases of Poultry: 13th edition 2013
Take Home• Good management and Biosecurity
Clinical signs and Lesions
List of Diseases
Sampling and treatment
Questions?