These are copies of the PowerPoint slides (2 per page) from a presentation prepared for the Blue Ribbon Sheep Forum in Storrs, CT (2/25/12).

1. Integrated parasite management in sheep 2/25/12
SUSAN SCHOENIAN (Shāy‐nē‐ŭn)
Sheep & Goat Specialist
Western Maryland Research & Education Center
sschoen@umd.edu ‐ www.sheepandgoat.com
Alt.
forages
Deworm
D Browsing
i
“Natural” Clean
anthelmintics pastures
Integrated
means
combining and
coordinating
Refugia
IPM Nutrition
diverse
elements Zero
grazing
Manage
‐ment
into a whole.
Host
Genetics
Internet definition immunity
Grazing
Mgt.
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2. Integrated parasite management in sheep 2/25/12
Integrated pest management
(IPM) is a method of controlling
parasites in a population of CHEMICAL
animals by using a combination Deworm
of chemical and non‐chemical
methods. INTEGRATED
[Pfizer Animal Health] NON‐CHEMICAL
alternative forages;
browsing; clean pastures;
coccidiostats; delayed grazing;
FAMACHA©; Five Point Check©; genetic
Fi P i t Ch k ti
selection; host resistance; low stocking rates;
management; multispecies grazing; “natural”
anthelmintics; nutrition; pasture rest and rotation;
grazing height; proper anthelmintic use; protein
supplementation; refugia; sanitation; and zero grazing.
Though it varies by farm,
worms have developed
h d l d
resistance to ALL of the
anthelmintics.
It’s not sustainable (or
sometimes even possible)
to control internal parasites
with drugs alone.
There is a growing interest
among producers and
consumers alike for more
natural methods of pest
control.
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3. Integrated parasite management in sheep 2/25/12
Pasture
Plants Animal
Soil Immunity
Behavior
Possible
clinical
disease
Parasite
Biology
Life cycle Weather
Temperature
Moisture
g o ga s
A living organism
(generally
undesirable) that
exists by stealing
the resources
produced or
collected by
another living
organism.
[Wiktionary]
barber pole worms in abomasum
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4. Integrated parasite management in sheep 2/25/12
EXTERNAL (ECTO)
INTERNAL (ENDO)
A parasite that lives inside A parasite that lives on
another organism. the outside of the animal.
barber pole worm ticks, lice, mites, flies, etc.
There is a species from each kind that is especially problematic for sheep .
PROTOZOA
HELMINTHS Single‐cell
Multi‐cellular
Coccidia
1. Nematodes Giardia
Roundworms Cryptospordium
2. Cestodes
Tapeworms
3. Trematodes
Flukes VS.
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5. Integrated parasite management in sheep 2/25/12
Haemonchus contortus
Barber pole worm Bunostomum
Hookworm
H k
Cooperia
Small intestinal worm
Nematodirus
Threadneck worm
Oesophagostomum
Nodule worm
Strongyloides
gy
common threadworm
Trichostronylus Trichuris ovis
hair or bankrupt worm
whipworm
Telodorsagia (Ostertagia)
medium or brown stomach worm
Lungworms
Paralaphostrongylus tenius
Meningeal worm
Most deadly.
Found in abomasum
Blood‐sucker
Short, direct life cycle
Prolific egg producer
Barber pole worm
Requires warmth and moisture Image source: Dr. Nabavi (Iran)
g
to complete its life cycle.
t l t it lif l
Warm, moist climates
Summer rainfalls
As a mechanism of survival, can go into a hypobiotic (arrested) state.
Is adapting to cooler climates global climate change (?)
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6. Integrated parasite management in sheep 2/25/12
CLINICAL SIGNS
Sudden death
Gradual weight loss
Weakness
Poor stamina
Diarrhea constipation
Anemia
FAMACHA© score 4 or 5
Sub‐mandibular edema
“bottle jaw”
Death
Same genus.
Affect abomasum1
and small intestines2.
Similar life cycle
as barber pole worm
Mixed infections with barber pole
worm are common.
Cause reduced performance, ill‐
C d d f ill
thrift and dagginess (diarrhea),
occasionally death.
Under the microscope, eggs look
the same as barber pole
worm eggs.
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7. Integrated parasite management in sheep 2/25/12
Roundworm that normally
infects white tail deer,
infects white tail deer
but causes little problems.
But causes severe neurological
disease when it infects an
abnormal host, such as a sheep.
Has indirect life cycle with
g
terrestrial snails and slugs
serving as the intermediate hosts.
10‐14 days after ingestion of an infective snail or slug,
the parasite migrates to the spinal cord (central nervous
system) and begins causing damage to neurological tissue.
Sheep are a dead end host. Must necropsy to confirm diagnosis.
CLINICAL SIGNS
Variable and similar to other
V i bl d i il t th
neurological diseases, such as
polio, listeriosis, and rabies.
Weakness
Lameness
Circling
Blindness
Head tilt
Abnormal behavior
Paralysis
Death
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8. Integrated parasite management in sheep 2/25/12
TREATMENT ‐‐ early ‐‐ PREVENTION
Exclude deer
E l d d
Repetitive, high doses of
anthelmintics [Rx] Don’t graze in woods or near
Ivermectin for 5 days ponds.
Fenbendazole for 5 days
Avoid grazing poorly‐drained
All anthelmintics have been pastures.
used to treat meningeal
worm infections. Reduce snail, slug population.
Anti‐inflammatory drugs [Rx] Preventative treatments with
anthelmintics
Regular deworming will promote
There is no scientific evidence development of anthelmintic‐
that any of the various resistant GI worms.
treatment protocols are
effective.
Indirect life cycle, with
pasture mites serving as the
intermediate host.
Worm segments are visible in
feces (gross!).
Generally non‐pathogenic
(disease‐causing).
y
Generally no benefit to
treatment for tapeworms
alone.
Can treat with fenbendazole
(SafeGuard®), albendazole
(Valbazen®, or praziquantel.
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9. Integrated parasite management in sheep 2/25/12
Indirect life cycle, with Image source:
gastropods serving as the http://www.flickr.com/photos/peteredin/3386220058/
http //www flickr com/photos/peteredin/3386220058/
intermediate host.
Can be found everyone, but are
mostly a problem in the Gulf
States and Pacific Northwest, i.e.
cool, wet climates.
Clinical symptoms include
anemia, bottle jaw, and weight
loss
loss.
Liver flukes can’t be found in a
normal fecal egg flotation.
Treat with albendazole
(Valbazen®) or Clorsulon [Rx].
Single‐cell, spore‐
forming protozoan
parasite.
Complicated life cycle
with many stages and
both sexual and asexual
reproduction
Approximately 21 days
10 species known to
infect sheep and goats.
Not all are pathogenic
Host‐specific.
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10. Integrated parasite management in sheep 2/25/12
Subclinical
(usually goes undetected ‐ most costly)
Poor performance
Performance set‐back
(even after treatment)
Clinical
Failure to thrive
Ill‐thrift
Open‐fleeced
Dagginess
Diarrhea
Anorexia
Anemia
Dehydration
Death
PREVENTION TREATMENT
Coccidiostats in feed, Drench with Corid
D h i h C id
mineral, or water. (amprolium) or Sulfa drugs
Bovatec® (lasalocid) (Albon®, Di‐methox) [Rx]
Supportive therapy
Deccox® (decoquinate)
Rumensin® (monensin) [Rx]
Corid (amprolium) [Rx]
Good management
Good sanitation
Proper stocking rates
Coccidiostats, especially Rumensin® can be toxic to horses and dogs.
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11. Integrated parasite management in sheep 2/25/12
FECAL EGG COUNTS (FEC) LARVAL ID
To differentiate between To differentiate between strongyle
strongyle (stomach) and (stomach) worms (H. contortus,
tapeworm eggs and coccidia Teladorsagia, and trichostrongyles)
oocytes. ▪ University of Georgia
▪ Other universities
Can’t differentiate between
strongyle (stomach) worm
eggs except Nematodirus)
gg p ) LECTIN‐STAINING TEST
1. Do‐it‐yourself Determine percent of Haemonchus
2. Public lab contortus eggs in a fecal sample
3. Diagnostic lab
Oregon State University
4. Private lab
University of Georgia
5. Veterinarian
Host immunity
Management
M
Clean or safe pastures
Multi‐species grazing
Pasture rest and rotation
Alternative forages
Nutritional management
Zero grazing
Genetic selection
Manage refugia
Targeted selective
treatment
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12. Integrated parasite management in sheep 2/25/12
Sheep have several
defense mechanisms
for dealing with
internal parasites:
1. Immune exclusion
2. Self‐cure
3. Immunity
a) Innate
b) Acquired
IMMUNE EXCLUSION
SELF‐CURE PHENOMENON
g
Ingested larvae fail to
establish in heavily Adult nematodes are
infected animals. spontaneously expelled
when there is a massive
larval invasion over a
very short exposure
period.
Usually observed after
a heavy rain.
a heavy rain
Why does it occur (?)
▪ Increase in
abomasal pH
▪ IgE mediated
hypersensitivity
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13. Integrated parasite management in sheep 2/25/12
St. Croix lambs
ACQUIRED
Immunity that is not
inherited.
Immunity that is acquired
INNATE (INBORN, NATURAL) during life.
Immunity that results from
Infection is limited during exposure to the disease.
the initial exposure.
Immunity that occurs
naturally as part of an
individual’s genetic
make‐up. Crossbred lambs
Develops with advancing age
p p
and parasite exposure.
Not until >4 months of age,
depending upon breed and
nematode species.
Preventative anthelmintic
treatments interfere with the
development of immunity.
Adults are generally immune
to parasites, but under stress
to parasites but under stress
can break down.
Sheep have a weaker degree
of immunity than other
livestock, except for goats.
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14. Integrated parasite management in sheep 2/25/12
Lasts for about 4 weeks
May occur earlier (in
pregnancy) if ewes are
underfed or under stress.
Primary source of infection
for new crop of lambs.
Cause (?) Hypothesis:
Lactation after pregnancy
Increasing prolactin levels
Reduction in IgA antibodies associated
with transfer of maternal antibodies in
colostrum
If lambing occurs in the
p g,
spring, it will coincide
with the maturation
and egg production
from previously
arrested worm larvae.
Management strategies
1. Deworm all ewes prior to
parturition with an
anthelmintic that is effective
against hypobiotic larvae.
2. Increase protein level of ration
during late gestation (by 30%).
3. Selective deworming using
FAMACHA© system and/or
Five Point Check©.
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15. Integrated parasite management in sheep 2/25/12
MORE SUSCEPTIBLE MORE RESISTANT
Weaned lambs Mature sheep
Bummer lambs Dry ewes
Late‐born lambs Pet sheep
Yearlings Mature wethers
High‐producing females Sheep in good body
Periparturient ewe condition
Thin animals Fat sheep
Geriatric sheep
Unadapted breeds
Stressed animals
Good sanitation
Use feeders
Clean water
Avoid overgrazing
Do not graze below
2 inches.
Time lambing to
minimize parasite
infections.
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16. Integrated parasite management in sheep 2/25/12
Pasture rotation is a
gy
recommended strategy for
controlling internal parasites
ll l
because it allows the use of
cleaner (rested) pastures.
Intensive rotational grazing may
not help to reduce parasitism
unless rest periods are long
enough.
Due to increased stocking rates,
management intensive grazing
may increase internal parasite
problems in sheep and lambs.
It takes about 2 months of rest
for a contaminated pasture to
become relatively “clean” for
sheep grazing.
A pasture that has not been grazed by
sheep (or goats) for the past 6 to 12
months.
h
A pasture that has been grazed by
adult cattle and/or horses for the past
6 to 12 months.
New pasture
A pasture that has been renovated
with tillage.
A pasture in which a hay or silage crop
h h h l
has been removed.
A pasture that has been rotated with
row crops.
A pasture that has been burned.
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17. Integrated parasite management in sheep 2/25/12
Livestock that browse have
problems.
fewer parasite problems
Livestock grazing tall-growing
forages will have less parasite
problems.
80% of parasite larvae is found in
the first two inches of vegetative
growth.
Grazing tanniferous forages may
g g y
reduce the effects of parasitism.
Sericea lespedeza
Chicory
Birdsfoot trefoil
Sheep and goats share the same
parasites, but they are different
from the parasites that affect
adult cattle and horses.
Producers who graze multiple
species of livestock report fewer
parasite problems with small
ruminants.
Cattle and horses “vacuum”
sheep/goat pastures of infective
worm larvae.
Sheep, goats, and cattle have
complementary grazing habits.
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18. Integrated parasite management in sheep 2/25/12
Animals on a high plane of nutrition
and in better body condition are
better able to withstand worm
b tt bl t ith t d
burdens.
Nutrition in early pregnancy (fat
stores) can affect the immune
response to internal parasites.
Sheep receiving higher levels of
protein prior to lambing have lower
fecal egg counts.
Supplementing grazing lambs with
protein has been shown to reduce
t i h b h t d
fecal egg counts.
Nutritional supplementation is most
likely to be beneficial when pregnant
females and young animals are below
optimal body condition at a time
when pasture quality and/or quantity
is limited.
Sheep raised in confinement
or dry lot (zero grazing) tend
to have fewer worm
problems.
Sheep put in confinement or
dry lot do not usually get re-
infected with worms.
Coccidiosis could still be a
problem, if preventative
measures are not taken.
Good sanitation
Proper feeders
Coccidiostats
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19. Integrated parasite management in sheep 2/25/12
Resistance
Ability of host to
Abili f h
resist infection
Measured by fecal
egg counts (FEC‐EPG).
Resilience
Ability of host to withstand
g
challenge and/or infection.
For barber pole worm:
measured by packed cell
volume (PCV) and
estimated by FAMACHA©
eye anemia scores.
St. Croix
Breeds vary in their
resistance and resilience
i d ili
to gastro‐intestinal
parasites.
1. Hair sheep
(tropical or West
g )
African origin)
2. Gulf Coast Native
3. Katahdin
4. Dorper
Others (?)
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20. Integrated parasite management in sheep 2/25/12
There is as much
difference within breeds
as between breeds.
The 80‐20 rule
Approximately 20 percent of
the flock sheds 80 percent of
the eggs onto pasture.
Parasite resistance is are
moderately‐heritable.
H2 = 0.22‐0.63 (avg. 0.25)
Selection for parasite
resistance will not adversely
affect the growth of lambs
or fertility of ewes.
Do not deworm on a regular
schedule.
Do not deworm all animals in a
group.
Do not return treated animals to
a clean pasture.
Give all anthelmintics orally at
the proper dose.
Do not underdose.
Deworm new animals with
anthelmintics from 2‐3 different Without refugia, worms will eventually
chemical classes. be resistant to all anthelmintics.
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21. Integrated parasite management in sheep 2/25/12
Point What to check Which parasites
Paling of ocular
P li f l
membranes Barber pole worm
1 Eye
FAMACHA© eye anemia Liver fluke
score
2 Back Body condition score All
Brown stomach worm
Dag score
Hair worm
3 Rear
R fecal soiling
f l ili
Threadneck worm
evidence of scouring
Nodule worm
Sub‐mandibular edema Barber pole worm
4 Jaw
(bottle jaw) Liver fluke
5 Nose Nasal discharge Nasal bots
Packed cell Treatment
Eye lid color
volume recommendation
1 Red > 28 Optimal No
2 Red‐Pink 23‐27 Acceptable No
3 Pink 18‐22 Borderline ?
4 Pink‐White 13‐17 Dangerous Yes
5 White < 12 Fatal Yes
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22. 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 p
pressure Cannot be
Maximally Thick
developed
d l d
felt at all
5 Not detectable Convex Very thick
Treatment
Dag score Description
recommendation
0 No fecal soiling No indication for treatment
1 Very slight soiling on edge of tail No treatment
Slight soiling on edge of tail and on
2 each side
Usually no treatment
Moderate soiling of tail and wool
3 Dag formation
Consider treatment
Severe soiling extending far into wool Treatment, crutching
4 Severe dag formation recommended
Very severe Treatment and crutching
5 watery diarrhea extending to hocks essential
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23. Integrated parasite management in sheep 2/25/12
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24. Integrated parasite management in sheep 2/25/12
Indicates “potential”
parasite burden in
it b d i
animal.
Indicates potential
parasite contamination.
Use to determine level
of drug efficacy.
of drug efficacy
Use to determine
genetic differences in
parasite resistance
among animals.
Fecal egg counts are not
always well‐correlated
always well correlated
with disease.
Presence of eggs does not
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.
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25. Integrated parasite management in sheep 2/25/12
1)Benzimidizoles
)
2)Nicotinic agonists
3)Macrocylic lactones
y
25

26. Integrated parasite management in sheep 2/25/12
)
1) Fenbendazole
SafeGuard®,
Panacur®
[Rx]
2) Albendazole
Valbazen®
3) Oxyfendazole
Synanthic®
[Rx]
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
d i fi t d f
pregnancy or ram removal.
Widespread resistance
Resistance is caused by
dominant gene
26

27. Integrated parasite management in sheep 2/25/12
1) Imidazothiaoles (IMID)
a) Levamisole
Prohibit®, Levasol®
2) Tetrahydropyrimidines
(TETR)
a) Morantel [Rx]
Rumatel®
b) Pyrantel [Rx]
Strongid®
Levamisole
Clear drench
Cl d h
Water soluble
Broad spectrum of activity
Not effective against
arrested larvae
Narrower margin of safety
Resistance reported
Resistance is caused by a
R i t i d b
recessive gene
Morantel and Pyrantel
Not effective against
larval stages of worms.
27

28. Integrated parasite management in sheep 2/25/12
1) Avermectins
a) Ivermectin
Ivomec®
b) Doramectin [Rx]
Dectomax®
2) Milbemycins
a) Moxidecin
Cydectin®
Quest® [Rx]
Broad spectrum
Wide margin of safety
Effective against (biting)
external parasites
Persistent activity
Widespread resistance,
p ,
reported especially
ivermectin
Resistance is caused by
dominant gene
28

29. Integrated parasite management in sheep 2/25/12
1) DRENCHRITE® 2) FECAL EGG COUNT
LARVAL DEVELOPMENT ASSAY REDUCTION TEST (FECRT)
An in vitro test for the detection Comparison of before and
of resistance to all anthelmintic after fecal egg counts
groups.
Benzimidizoles
7 days post‐treatment
Need pooled fecal sample from 10
Levamisole
or more animals (minimum of 6)
7 days post‐treatment
at least > 350 epg
>500 epg preferred Avermectins
14 days post‐treatment
▪ Animals with FAMACHA© scores of
3, 4, or 5 are more likely to have Should include “control”
higher egg counts if barber pole
worm is the primary parasite. (untreated) animals in testing.
Weigh animals to determine
proper dose.
proper dose
Do not underdose.
Use proper drench technique.
Fast animals prior to
treatment with ivermectin or
albendazole.
Give multiple anthelmintics
Synergetic effect
Maximize refugia
29

30. Integrated parasite management in sheep 2/25/12
An anthelmintic acts to expel
or destroy parasitic worms.
Using this definition, there
aren’t any consistently
effective “natural”
anthelmintics.
An animal that is clinically
parasitized should be treated
with a “chemical” dewormer.
Haemonchosis
They may not treat a
clinically parasitized animal,
clinically‐parasitized animal,
but they may reduce the
number of animals that
require treatment.
Disruption of parasite
life cycle (on pasture)
▪ Eat larvae or eggs
gg
▪ Inhibit larvae development
▪ Inhibit egg hatching
Strengthening of the
immune system.
An increasing number of scientific studies are being conducted to identify compounds which
may have anthelmintic‐like properties. Current claims are largely antidotal.
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31. 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
Nematode trapping f ng s
Copper oxide wire particles
Copper sulfate
Tobacco (nicotine sulfate)
Sericea lespedeza
Zolvix® drench (Monepantel)
Amino‐Acetonitrile (ADD) class
A i A t it il (ADD) l
First new anthelmintic since
1980’s
Unique mode of action
Targets a receptor that
paralyzes the worm
Effective against worms that are
resistant to other anthelmintics.
h h l
Currently undergoing
testing in the U.S.
Approval for sheep, if/when [?]
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32. Integrated parasite management in sheep 2/25/12
Thank you for your
attention.
Any questions?
Susan Schoenian
sschoen@umd.edu
www.sheepandgoat.com
32