♫ bad bugs, bad bugs, whatcha gonna do? ♪ : parasites in sheep

♫ 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