♫ Bad Bugs, Bad Bugs, Whatcha Gonna Do? ♪ : Parasites in
SheepDr Chris Clark
WCVMUniversity of Saskatchewan
Sheep Parasites
The price of doing business!
PGE Coccidiosis Tapeworms Fluke Skin parasites
CEST
ODIASIS/MONEZ
IA EX
PANSA
COCCIDIOSIS
CRYPT
OSPORIDIOSIS
/CRYPTOSP
ORIDIUM
GIARDIASIS/G
IARDIA SPP.
NEMATO
DIASIS/HAEM
ONCHUS CONTO
RTUS
NEMATO
DIASIS/NEM
ATODIRUS S
PP.
NEMATO
DIASIS/OST
ERTA
GIA OSTER
TAGI
NEMATO
DIASIS/OTH
ER
TREM
ATODIASIS
/FASC
IOLOIDES
MAGNA0
5
10
15
20
25
30
35
40
CaprineOvine
There’s a problem When we think of
parasites we think of drugs
Minimal drugs licensed for parasites for sheep in Canada
What does this mean for a sheep producer?
Drugs used in food animals are federally regulated
Only a veterinarian can prescribe extra-label drug use
Its more complicated Drugs
Identified by DIN number on packaging
Extra-label use permitted with veterinary prescription and withdrawal period
Pesticides
Identified by PCP number on package
No extra-label drug use permited
Antibiotic labels tell you all you need to know
SC = under the skinIM = in the muscleIV = in the vein
Treatment options for sheep are limited
You need a veterinarian to prescribe parasite treatments Use gFARAD for withdrawal information
Implications
The Canadian Prairies
Good for sheep Bad for most
parasites “its’s a dry cold”
It is not bad luck it is bad management
Coccidiosis
Mainly a problem of intensively raised lambs
Especially indoors
Outdoors needs specific conditions
Onset early as 8d Typically 4-6 weeks
Severe diarrhea +/- blood
Tenesmus
Morbidity high, mortality low
Coccidiosis
Etiology E. cradallis, E.
ovinoidalis
Diagnosis Epidemiology, fecal,
PM
Not all that easy!
Management Avoid the epidemiology
Use of coccidiostats Deccox Baycox Monensin Amprolium
problems
Treatment TMS
Means different things in different regions
Teladosagia (ostertagia) Haemonchus Nematodirus Trichostrongylus
Parasitic gastro-enteritis (PGE)
Eggs passed in feces Hatch and develop to L3 on pasture L3 ingested Develop to L5 – adult in host causing disease Pass eggs in feces
Hypobiosis
Small ruminants – Periparturient egg rise is significant Adults develop some immunity
Trichostrongyloidea
Canadian Prairies
Egg –L3 development Requires heat and
humidity
Haemonchosis
Barbers pole worm Found in abomasum
Blood sucker Prolific
Results Ill thrift Anemia, bottle jaw Sudden death
Eggs passed in feces must develop to L3 on pasture 5 day minimum
Requirements Heat 18-26C (< 5 dormant, <10 nothing) Humidity 100%
Canadian prairies –lucky to get one cycle
Epidemiology
Significance
Most years disease is rare
If the weather is right you have a problem
Haemonchus diagnosis
Reality PM
Clinical signs
High egg count
Haemonchus control
Traditionally Deworm Deworm Deworm Repeat as required
Nematode of the abomasum Larval forms disrupt acid production
Type 1 disease Diarrhea and weight loss
Type 2 disease Early spring – bottle jaw
Teladosagia
Natural cycle in ideal conditions
Deworm ewes at lambing
Deworm lambs repeatedly throughout late summer and fall
Traditional control
Nematodirus
Intestinal worm Egg development in 2-3
months
N. battus – different epidemiology
Diagnosis difficult as disease is prepatent Egg looks like liver fluke
Intestinal worm with epidemiology and effects similar to Teladosagia
Eggs are indistinguishable
Trichostrongylus
Understanding the epidemiology
All research is done in a different climate
Periparturient egg rise Egg – L3 development on pasture Cycling in lambs Some winter die off
Controlling PGE
Periparturient egg rise Can last 8 weeks
Deworming ewes in association with parturition
Can be used to minimize pasture contamination in late spring
Using epidemiology to control PGE
Using epidemiology to control PGE
Deworm lambs at weaning and move to new pasture/feedlot
BZ- Benzimidazoles
LM – Levamisol, Pyrantel, Morantel
AV- Avermectins
Anthelmintics
Do you have a problem?
Fecal egg count reduction test1. FEC2. Weigh and dose3. Wait 10d then redo FEC4. Should be >85% reduction in egg count
Anthelmintic resistance
Biosecurity Dose all new arrivals on arrival
Weigh and dose
Dose on an empty stomach
Wait 2-3 days before turn out
Anthelmintic resistance
Weigh and dose
Avoid rotation of dewormer classes
Dose when needed (egg counts, FAMACHA, BCS) Refugia
Dose and move
Anthelmintic resistance
Intestinal
Cystic Disease
Tapeworms
Monezia Not important
Intestinal tapeworms
Intermediate hosts
Taenia ovis
Dog - sheep
The costs of disease
2009 – 270 lambs in the 1st 6 months
”In heavy infestations the carcass is condemned.It is commonly considered that an animal isheavily infested if lesions are discovered in two ofthe usual inspection sites including the massetermuscle, tongue, oesophagus, heart, diaphragmor exposed musculature and in two sites duringincision into the shoulder and the rounds.Carcasses with C. ovis infestations may not beacceptable for export.”
Traditional control
Typified by Australia and New Zealand
Routine deworming Mandated with appropriate products
Feed control Freezing Cooking
Liver fluke
Complex life cycle
Absolute requirement for snail Lymnaea truncatula
Liver fluke - disease
Acute Sudden death at
pasture Sub acute
Poor doing fall/winter
Chronic Anemia,
hypoproteinemia poor BCS
Fascioloides Magna
Sheep is an aberrant host Continual fluke migration
Presentation Death
Control Avoidance f snail areas Triclabendazole
Liver Fluke Control
Albendazole Adult fluke only
Triclabendazole V effective Not in Canada
Skin parasites
Lice Keds/ticks Mites Flies
Lice
Bovicola ovis – chewing
Linognathus spp. -sucking
Keds
Melophagus ovinus
Ticks
Ticks latch on and feed
Have 8 legsDo not live on the goat
Mites
Sheep scab
Psoroptes ovis
Treat with an avermectin twice (7d apart)
Fly strike in sheep
Management problem
Severe welfare issue