1. Integrated parasite management combines chemical and non-chemical methods to control internal parasites in sheep populations. This includes strategies like targeted selective treatment, pasture management, nutrition, and genetic selection.
2. The most problematic internal parasites for sheep are gastrointestinal nematodes like the barber pole worm, which can cause weight loss, diarrhea, and death. External parasites like ticks and flies are also an issue.
3. Proper management techniques include clean pastures, multi-species grazing, pasture rotation, and selective treatment based on individual animal assessments like the FAMACHA system. These integrated strategies are needed due to increasing anthelmintic resistance.
3. Integrated parasite management in sheep 2/25/12
Roundworm that normally Indirect life cycle, with
infects white tail deer, pasture mites serving as the
but causes little problems. intermediate host.
But causes severe neurological Worm segments are visible in
feces (gross!).
disease when it infects an
abnormal host, such as a sheep. Generally non‐pathogenic
(disease‐causing).
Has indirect life cycle with
terrestrial snails and slugs Generally no benefit to
serving as the intermediate hosts. treatment for tapeworms
alone.
10‐14 days after ingestion of an infective snail or slug,
the parasite migrates to the spinal cord (central nervous Can treat with fenbendazole
system) and begins causing damage to neurological tissue. (SafeGuard®), albendazole
(Valbazen®, or praziquantel.
Sheep are a dead end host. Must necropsy to confirm diagnosis.
CLINICAL SIGNS Indirect life cycle, with Image source:
Variable and similar to other gastropods serving as the http://www.flickr.com/photos/peteredin/3386220058/
intermediate host.
neurological diseases, such as
polio, listeriosis, and rabies. Can be found everyone, but are
mostly a problem in the Gulf
Weakness
W k States and Pacific Northwest, i.e.
States and Pacific Northwest i e
cool, wet climates.
Lameness
Clinical symptoms include
Circling anemia, bottle jaw, and weight
Blindness loss.
Head tilt Liver flukes can’t be found in a
Abnormal behavior normal fecal egg flotation.
Paralysis Treat with albendazole
Death (Valbazen®) or Clorsulon [Rx].
TREATMENT ‐‐ early ‐‐ PREVENTION
Single‐cell, spore‐
Exclude deer forming protozoan
Repetitive, high doses of parasite.
anthelmintics [Rx] Don’t graze in woods or near
Ivermectin for 5 days ponds.
Fenbendazole for 5 days Complicated life cycle
Avoid grazing poorly‐drained with many stages and
All anthelmintics have been pastures. both sexual and asexual
used to treat meningeal reproduction
worm infections. Reduce snail, slug population.
Approximately 21 days
Anti‐inflammatory drugs [Rx] Preventative treatments with
anthelmintics
Regular deworming will promote
10 species known to
There is no scientific evidence development of anthelmintic‐ infect sheep and goats.
that any of the various resistant GI worms.
Not all are pathogenic
treatment protocols are
effective. Host‐specific.
3
4. Integrated parasite management in sheep 2/25/12
Subclinical Host immunity
(usually goes undetected ‐ most costly)
Poor performance Management
Performance set‐back Clean or safe pastures
(even after treatment)
Multi‐species grazing
Clinical
Cli i l Pasture rest and rotation
Failure to thrive Alternative forages
Ill‐thrift Nutritional management
Open‐fleeced Zero grazing
Dagginess
Diarrhea
Genetic selection
Anorexia Manage refugia
Anemia Targeted selective
Dehydration treatment
Death
PREVENTION TREATMENT
Drench with Corid Sheep have several
Coccidiostats in feed,
mineral, or water. (amprolium) or Sulfa drugs defense mechanisms
Bovatec® (lasalocid) (Albon®, Di‐methox) [Rx] for dealing with
Supportive therapy internal parasites:
i t l it
Deccox® (decoquinate)
Rumensin® (monensin) [Rx]
Corid (amprolium) [Rx]
1. Immune exclusion
Good management 2. Self‐cure
Good sanitation 3. Immunity
Proper stocking rates a) Innate
b) Acquired
Coccidiostats, especially Rumensin® can be toxic to horses and dogs.
IMMUNE EXCLUSION
FECAL EGG COUNTS (FEC) LARVAL ID SELF‐CURE PHENOMENON
Ingested larvae fail to
To differentiate between To differentiate between strongyle establish in heavily Adult nematodes are
strongyle (stomach) and (stomach) worms (H. contortus, infected animals. spontaneously expelled
tapeworm eggs and coccidia Teladorsagia, and trichostrongyles) when there is a massive
oocytes. ▪ U i
University of Georgia
it f G i larval invasion over a
▪ Other universities very short exposure
Can’t differentiate between period.
strongyle (stomach) worm Usually observed after
eggs except Nematodirus) LECTIN‐STAINING TEST a heavy rain.
1. Do‐it‐yourself Determine percent of Haemonchus Why does it occur (?)
2. Public lab ▪ Increase in
contortus eggs in a fecal sample abomasal pH
3. Diagnostic lab
Oregon State University ▪ IgE mediated
4. Private lab
University of Georgia hypersensitivity
5. Veterinarian
4
6. Integrated parasite management in sheep 2/25/12
Pasture rotation is a
recommended strategy for Sheep and goats share the same
controlling internal parasites parasites, but they are different
because it allows the use of
cleaner (rested) pastures. from the parasites that affect
adult cattle and horses.
Intensive rotational grazing may
not help to reduce parasitism Producers who graze multiple
P d h lti l
unless rest periods are long species of livestock report fewer
enough. parasite problems with small
Due to increased stocking rates, ruminants.
management intensive grazing
may increase internal parasite Cattle and horses “vacuum”
problems in sheep and lambs. sheep/goat pastures of infective
worm larvae.
It takes about 2 months of rest
for a contaminated pasture to Sheep, goats, and cattle have
become relatively “clean” for complementary grazing habits.
sheep grazing.
A pasture that has not been grazed by Animals on a high plane of nutrition
sheep (or goats) for the past 6 to 12 and in better body condition are
months. better able to withstand worm
burdens.
A pasture that has been grazed by
adult cattle and/or horses for the past Nutrition in early pregnancy (fat
6 to 12 months. stores) can affect the immune
response to internal parasites.
New pasture Sheep receiving higher levels of
protein prior to lambing have lower
A pasture that has been renovated fecal egg counts.
with tillage.
Supplementing grazing lambs with
A pasture in which a hay or silage crop protein has been shown to reduce
has been removed. fecal egg counts.
A pasture that has been rotated with Nutritional supplementation is most
row crops. likely to be beneficial when pregnant
females and young animals are below
A pasture that has been burned.
optimal body condition at a time
when pasture quality and/or quantity
is limited.
Livestock that browse have
fewer parasite problems. Sheep raised in confinement
or dry lot (zero grazing) tend
Livestock grazing tall-growing to have fewer worm
forages will have less parasite problems.
problems.
Sheep put in confinement or
80% of parasite larvae is found in dry lot do not usually get re-
the first two inches of vegetative infected with worms.
growth.
Coccidiosis could still be a
Grazing tanniferous forages may problem, if preventative
reduce the effects of parasitism. measures are not taken.
Sericea lespedeza Good sanitation
Chicory Proper feeders
Birdsfoot trefoil Coccidiostats
6
8. Integrated parasite management in sheep 2/25/12
Transverse
Spine Muscle Fat
processes
Fingers easily pass
Individually clearly felt,
1 sharp, obvious
underneath Very little No
Form a smooth line with
2 deep undulations
Smooth round edges Concave Very thin
Well covered Not concave
Only slightly detectable
3 undulations
have to push firmly to
get fingers underneath Not convex
Moderate
Only detectable with firm
4 pressure Cannot be
Maximally Thick
developed
felt at all
5 Not detectable Convex Very thick
Treatment
Dag score Description
recommendation Indicates “potential”
parasite burden in
0 No fecal soiling No indication for treatment
animal.
1 Very slight soiling on edge of tail No treatment
Slight soiling on edge of tail and on
l h l d f l d
d cates pote t a
Indicates potential
2 each side
Usually no treatment parasite contamination.
Moderate soiling of tail and wool
3 Dag formation
Consider treatment
Use to determine level
Severe soiling extending far into wool Treatment, crutching of drug efficacy.
4 Severe dag formation recommended
Use to determine
5 Very severe
watery diarrhea extending to hocks
Treatment and crutching
essential
genetic differences in
parasite resistance
among animals.
Fecal egg counts are not
always well‐correlated
with disease.
Presence of eggs does not
gg
mean that the animal is
clinically parasitized and
needs treatment.
Absence of eggs or
oocytes (coccidia) does not
mean that the animal is
parasite‐free and not in
need of treatment.
8
9. Integrated parasite management in sheep 2/25/12
White dewormers
Water soluble
Broad spectrum
Wide margin of safety
Efficacy against
tapeworms
Efficacy against adult liver
flukes (albendazole)
Do not use albendazole
during first 30 days of
pregnancy or ram removal.
Widespread resistance
Resistance is caused by
dominant gene
1) Imidazothiaoles (IMID)
1)Benzimidizoles a) Levamisole
Prohibit®, Levasol®
2)Nicotinic agonists 2) Tetrahydropyrimidines
3)Macrocylic lactones (TETR)
a) Morantel [Rx]
Rumatel®
b) Pyrantel [Rx]
Strongid®
1) Fenbendazole Levamisole
Clear drench
SafeGuard®, Water soluble
Panacur® Broad spectrum of activity
[Rx] Not effective against
arrested larvae
2) Albendazole Narrower margin of safety
Valbazen® Resistance reported
Resistance is caused by a
3) Oxyfendazole recessive gene
Synanthic® Morantel and Pyrantel
[Rx] Not effective against
larval stages of worms.
9
11. Integrated parasite management in sheep 2/25/12
Herbal dewormers
[oils and seeds]
Artemisia genus (Wormword)
Garlic Papaya
Paprika Ginger
Pumpkin Mustard
Tanniferous forages
Nematode‐trapping fungus
Copper oxide wire particles
Copper sulfate
Tobacco (nicotine sulfate)
Sericea lespedeza
Zolvix® drench (Monepantel)
Amino‐Acetonitrile (ADD) class
First new anthelmintic since
1980’s
Unique mode of action
U i d f ti
Targets a receptor that
paralyzes the worm
Effective against worms that are
resistant to other anthelmintics.
Currently undergoing
testing in the U.S.
Approval for sheep, if/when [?]
Thank you for your
attention.
Any questions?
Susan Schoenian
sschoen@umd.edu
www.sheepandgoat.com
11