1. PARASITES AND GOATS
DAKOTA GOAT ASSOCIATION
STATE WIDE GOAT CONFERENCE - OCTOBER 20, 2017
SUSAN SCHOENIAN
Sheep & Goat Specialist
University of Maryland Extension
sschoen@umd.edu - (301) 432-2767 x343
www.wormx.info - www.sheepandgoat.com
2. PRESENTATION TOPICS
ā¢ American Consortium for Small Ruminant Parasite Control (ACSRPC)
ā¢ Overview
ā¢ Biology of parasites
ā¢ Anthelmintics (dewormers) 101
ā¢ Anthelmintic resistance
ā¢ Combination treatments
ā¢ Copper oxide wire particles
ā¢ Nematode trapping fungus
ā¢ Fecal egg counting
3. AMERICAN CONSORTIUM FOR SMALL
RUMINANT PARASITE CONTROL
A group of scientists, veterinarians, and extension specialists devoted to (1) developing
novel methods for sustainable control of gastro-intestinal nematodes in small ruminants
and (2) educating the stakeholders in the small ruminant industry on the most up-to-date
methods and recommendations for control of gastrointestinal nematodes.
4. WEB SITE
WORMX.INFO OR ACSRPC.ORG
Go-to place for information about internal parasites
Not Facebook or Google!
5. BLOG: https://www.wormx.info/blog
ā¢ Subscribe to WORMINFO
listserv to receive an email
when something new has
been posted to the web
site.
ā¢ To subscribe, send an
email to
listserv@listserv.umd.edu.
In the body of the message,
write subscribe
WORMINFO.
LISTSERV
RECENT ADDITIONS TO WEB SITE
BLOG AND LISTSERV
8. OVERVIEW OF PROBLEM
ā¢ Gastro-intestinal parasites are the primary
health problem affecting sheep and goats
worldwide.
ā¢ GI parasites can be an obstacle to
profitable and sustainable small ruminant
production in many climates and
production systems.
ā¢ Small ruminants are more susceptible to
parasitism than other farm livestock
ā¢ Goats are more susceptible than sheep.
ā¢ Problem is worsened by drug resistance.
9. GOATS AND PARASITES
WHY ARE THEY SO SUSCEPTIBLE?
ā¢ Goats are browsers or intermediate grazers.
ā¢ They rely on feeding strategies to avoid
ingestion of infective worm larvae, which are
found mostly in first two inches of vegetative
growth.
ā¢ Unlike sheep, goats are unable to reduce
establishment of infective worm larvae or to
expel adult worms.
ā¢ In goats, immunity is rarely completely effective
against worms.
ā¢ Exposure to worms is necessary to develop
immunity; low levels are insufficient.
12. USUALLY MAJOR
1. Haemonchus contortus
Barber pole worm
2. Trichostrongylus spp.
Black scour worm (bankrupt
worm)
3. Teladorsagia (Ostertagia)
Brown stomach worm
1. Cooperia
small intestinal
worm
2. Nematodirus
threadneck worm
3. Oesophagostomum
nodule worm
4. Bunostomum
hook worm
USUALLY MINOR
NEMATODES ā ROUNDWORMS - STRONGYLES
5. Trichuris ovis
whipworm
6. Strongyloides
threadworms
7. Lungworms
8. Parelaphostrongylus
tenuis
Meningeal worm
13. MAJOR ROUNDWORMS
ā¢ Haemonchus contortus
Barber pole worm
ā¢ Trichostrongylus spp.
Black scour worm
ā¢ Teladorsagia (Ostertagia)
Brown stomach worm
Eggs look the same; need to hatch larvae in order to differentiate species.
Trichostrongylus/Teladorsagia are often not differentiated even when doing larvae ID.
15. ROUNDWORMS CAN BE
HARD TO CONTROL
ā¢ Short, direct life cycles
ā¢ No intermediate host
ā¢ Ability to engage in hypobiosis
ā¢ Barber pole worm is prolific egg layer
ā¢ Goats slow to develop immunity.
ā¢ Compromised immunity of peri-
parturient female.
ā¢ Widespread and growing drug
resistance
17. HYPOBIOTIC LARVAE
Adult
worms in
GI tract
L4 larval
stage
L4 larvae in āarrested
developmentā
Eggs in
feces
During winter, most
larvae are in āarrested
development.ā Few
larvae survive
prolonged cold. This
allows worms to
survive over winter (as
hypobiotic larvae) and
re-infect pastures
following spring.
Hypobiotic larvae is
the primary means by
which worms survive
in a northern climate.
18. PERI-PARTURIENT EGG RISE (PPER)
ā¢ Loss of immunity during late gestation
and early lactation; occurs from several
weeks before to several weeks after
parturition
ā¢ Well-documented phenomenon in
sheep; also documented in goats.
ā¢ With spring kidding, PPER often
coincides with hypobiotic larvae
resuming their life cycle.
ā¢ Need to have a strategy for dealing with
periparutient egg rise.
ā¢ Primary source of pasture
19. COCCIDIA (EIMERIA SPP.)
THE OTHER BIG PARASITE PROBLEM
ā¢ Single-cell protozoan parasite.
ā¢ Has more complex life cycle than roundworms.
ā¢ Host-specific
ā¢ Not all species are pathogenic (harmful).
ā¢ Affects lambs/kids mostly before and after
weaning.
ā¢ Sheep develop strong and lifetime immunity;
goats probably less so.
ā¢ Causes diarrhea, but not always, and general ill-
thrift
ā¢ Associated with poor hygiene and management.
https://attra.ncat.org/attra-
pub/summaries/summary.php?pub=483
20. PREVENTION
ā¢ Good hygiene, nutrition, and
management.
ā¢ Coccidiostats in mineral, feed, or water
Need to feed or put in water before risk period
1. Lasalocid (BovatecĀ®) - sheep
2. Monensin (RumensinĀ®) - goats (ļ horses)
3. Decoquinate (DeccoxĀ®) - both
4. Amprolium (CoridĀ®) - ELDU, OTC
ā¢ Natural control
ā¢ Sericea lespedeza pellets
ā¢ Other (?)
ā¢ Amprolium (CoridĀ®)- ELDU, OTC
ā¢ Sulfa drugs (Di-MethoxĀ®) - ELDU, Rx, VFD
Damages lining of small intestines.
Damage can be permanent (āruntsā)
TREATMENT
COCCIDIOSIS
21. WHAT ABOUT TAPEWORMS?
MONIEZIA EXPANSA
ā¢ Tapeworms are the only parasite visible in the
feces. Diagnosed by seeing segments in
feces.
ā¢ Tapeworms tend to be non-pathogenic; not
harmful, but theyāre blamed for a lot, usually
no benefit to treatment (goats?).
ā¢ Lambs develop immunity at very young age.
ā¢ Tapeworms can cause mild unthriftiness and
digestive disturbances, intestinal blockages
(rare) and affect gut motility, predisposing
lambs to enterotoxemia (occasionally).
ā¢ Treat with albendazole (ValbazenĀ®) or
praziquantel (in some horse dewormers,
ELDU)
https://www.wormx.info/tapeworms
22. WHAT ABOUT MENINGEAL WORM?
PARALAPHOSTRONGYLUS TENIUS
ā¢ Parasite of white tail deer.
ā¢ Also called deer or brain worm.
ā¢ Sheep, goats, alpacas, and llamas are
all abnormal hosts.
ā¢ Infection requires an intermediate host,
terrestrial snail or slug.
ā¢ Causes various neurological symptoms.
ā¢ No diagnostic test in live animal.
ā¢ No FDA-approved or proven treatment.
ā¢ Cornell University has been evaluating
treatment protocols: fenbendazole
(SafeGuardĀ®) + anti-inflammatory drugs
(Dexamethasone or Banamine).
https://nydairyadmin.cce.cornell.
edu/uploads/doc_392.pdf
24. WHAT IS AN ANTHELMINTIC?
ā¢ Compound used to kill gastro-intestinal
parasites (worms) without harming host.
ā¢ More commonly called wormer, dewormer or
drench.
ā¢ Anthelmintics have different chemistries.
ā¢ Chemistry determines which worms they are
effective against, mode of action, and withdrawal
period(s).
ā¢ Anthelmintics are grouped by chemistries.
ā¢ There is cross-resistant among drugs in the
same groups, having the same modes of action.
25. THERE ARE THREE (SORT OF 4) āCHEMICALā
CLASSES OF DEWORMERS FOR SMALL
RUMINANTS (IN THE US).
GROUP 1
Benzimidazoles
(BZ)
GROUP 2
Macrocylic lactones (ML)
GROUP 3
Nicotinic agonists
Avermectins Milbemycins Imidazo-thiazoles Tetrahydro-pyrimidines
Fenbendazole
SafeGuardĀ®
PanacurĀ®
Ivermectin
IvomecĀ®
Moxidectin
CydectinĀ®
QuestĀ®
Levamisole
ProhibitĀ®
Leva-MedĀ®
TramisolĀ®
LevasolĀ®
Morantel tartrate
RumatelĀ®
Albendazole
ValbazenĀ®
Doramectin
DectomaxĀ®
Pyrantel
StrongidĀ®Eprinomectin
EprinexĀ®
Oxfendazole
SynanthicĀ®
26. ANTHELMINTICS FDA-APPROVED FOR GOATS
1
Benzimidazoles
3b
Morantel
Fenbendazole
SafeGuardĀ®
Albendazole
ValbazenĀ®
Feed premix
Rumatel
Adult worms ļ¼ Not approved ļ¼
Larvae (L4) ļ¼ Not approved sporadic
Hypobiotic larvae ļ¼ Not approved
Lungworms ļ¼ Not approved
Tapeworms Not labeled Not approved
Liver flukes Adult stage
Coccidia
External parasites
Persistent activity
Safety wide 10x (sheep)
pregnancy restriction
~20x (sheep)
Dosage 1.2 ml/50 lbs. 4 ml/100 lbs. Varies by product
Meat withdrawal 6 days 7 days 30 days
Milk withdrawal 0 days
27. EXTRA-LABEL ANTHELMINTICS FOR GOATS
1
Benzimidazoles
2a
Avermectins
IvomecĀ®
sheep drench
2b
Milbimycins
Moxidectin
CydectinĀ® sheep drench
3a
Levamisole
ProhibitĀ®
Leva-MedĀ®
Fenbendazole
SafeGuardĀ®
Albendazole
ValbazenĀ®
Adult worms ļ¼ ļ¼ ļ¼ ļ¼ ļ¼
Larvae (L4) ļ¼ ļ¼ ļ¼ ļ¼ Limited
Hypobiotic larvae ļ¼ ļ¼ ļ¼ ļ¼ Limited
Lungworms ļ¼ ļ¼ ļ¼ ļ¼ ļ¼
Tapeworms Double dosage ļ¼
Liver flukes Adult stage
Coccidia
External parasites Some
label for bot control
Some
Not labeled
Persistent activity ļ¼ ļ¼
Safety wide 10x
pregnancy
restriction
20x 5x 3x
Dosage 1.1 ml/25 lbs. 2 ml/25 lbs. 6 ml/25 lbs. 4.5 ml/25 lbs. Depends on
dilution
Meat withdrawal 16 days
(1 day for each additional day used)
9 days 14 days 17 days 4 days
Milk withdrawal 4 days
(1 day for each additional day used)
7 days 9 days 8 days 3 days
https://www.wormx.info/dewormers
29. IN WORM
ā¢ Worms develop resistance to drugs.
Canāt be killed!
Pass resistant genes onto next
generation.
ā¢ Some animals are more resistant to
parasites.
Ability to reduce parasite establishment.
Pass resistance genes onto next
generation.
IN ANIMAL
TWO KINDS OF RESISTANCE WHEN WE
TALK ABOUT INTERNAL PARASITES
30. WHAT IS ANTHELMINTIC
RESISTANCE?
ā¢ Genetic ability of a worm to survive a dose of
anthelmintic which would normally be
effective.
ā¢ Only worms that survive treatment carry
genes that confer resistance.
ā¢ Result of selection through exposure of worm
population to an anthelmintic.
ā¢ When more than 5 percent of worms are
ādrug tolerantā; i.e. failure to reduce FEC by
95% or more (some say 90%).
http://www.scops.org.uk/what-is-resistance.html
31. ANTHELMINTIC RESISTANCE
ā¢ In the US, worms have developed resistance to
all dewormers and dewormer classes, though it
varies by geographic region and farm.
ā¢ Worse in Southeast due to increased parasite risk
and need for deworming.
ā¢ Worse on farms that frequently deworm or use
improper deworming practices.
ā¢ Most farms have resistance to at least two
dewormers; some farms have resistance to all
dewormers/classes. 0
20
40
60
80
100
Benzimidazoles Ivermectin Levamisole Moxidectin
Maryland Virginia Georgia
32. WHAT ABOUT RESISTANCE IN MORE
NORTHERN CLIMATES?
Farm
Fenbendazole
%FECR
Ivermectin
% FECR
A 16 77
B 70 41
C 38 78
D 0 0
ā¢ There is growing suspicion
that the geographic range of
the barber pole worm is increasing
and that resistance to deworming
agents is on the rise.
ā¢ A pilot project in Alberta (2015)
showed that many Alberta sheep
flocks have high parasite burdens
and that ivermectin and fenbendazole
-resistant parasites may be common
in the province.
ā¢ NCAT is working with Montana State University Extension to determine
anthelmintic resistance in Montana, Wyoming, and Utah.
33. ANTHELMINTIC RESISTANCE IS
INEVITABLE, BUT CAN BE DELAYED.
Practices that accelerate development of resistant worms
1. Frequent deworming
2. Whole flock treatments
3. Calendar based treatments
4. Treat and move strategy
5. Rotating dewormers
6. Underdosing
7. Depositing drug in mouth instead of deep into oral cavity.
8. Use of persistent activity dewormers
9. Use injectable dewormers
10.Use pour-on dewormers.
11.Use of feed dewormers*
12.Improper storage of dewormers
34. FECAL EGG COUNT
REDUCTION TEST
ā¢ Compare before and after fecal egg counts
from same animals.
ā¢ Old protocol compared post-treatment FECs of
treated animals vs. control (untreated) group.
ā¢ ~15 animals per drug tested
ā¢ Minimum FEC of 250 epg*, preferably higher.
ā¢ Can use individual or pooled (composite)
samples.
ā¢ Cost varies. Can learn to do yourself or send to
parasitology lab.
ā¢ Labor-intensive laboratory test that
determines resistance to all dewormers
and classes from a single pooled fecal
sample (from ~10 animals).
ā¢ Minimum FEC of 500 epg.
ā¢ Also identifies larvae: % Haemonchus
Trichostrongyles eggs look the same.
ā¢ Test done exclusively by Dr. Ray Kaplanās
lab at the University of Georgia.
ā¢ $450 per sample
DRENCHRITEĀ® TEST
TWO WAYS TO TEST FOR
ANTHELMINTIC RESISTANCE
37. āTHERE NOW IS VERY STRONG
EVIDENCE THAT USING COMBINATION
TREATMENT IS THE BEST METHOD FOR
USING DEWORMERS AND SHOULD BE
INSTITUTED ON ALL FARMS
IMMEDIATELY.ā
DR. RAY KAPLAN, UNIVERSITY OF GEORGIA (JANUARY
2017)
http://www.wormx.info/combinations
38. RATIONALE FOR
COMBINATION TREATMENTS
ā¢ Most farms have resistance to at
least two of the three major groups of
dewormers; some have resistance to
all.
ā¢ At first introduction, drug efficacy is over
99%.
ā¢ Once efficacy falls below 95%, drug
resistance is present, though drug is still
useful for treatment.
ā¢ As effectiveness of dewormer decreases
(<95%), as it is used more, it provides less
and less benefit to animals.
ā¢ Below 50%, it is no longer effective as sole
There is already resistance to ZolvixĀ® in
other countries. ZolvixĀ® is not sold in US.
39. WHY GIVE COMBINATION
TREATMENTS?
ā¢ Contrary to popular belief, rotating between
dewormers will not prevent resistance from
developing. In fact, it will allow worms to develop
resistance to multiple drugs simultaneously. It is
no longer recommended.
ā¢ Research done in New Zealand has shown that
the best approach is to use several different
dewormers at one time as a combination
treatment.
ā¢ When combined with ābest management
practicesā (that help to maintain refugia),
combination treatments may improve drug
efficacy and result in a reversion back toward
susceptibility.
Most dewormers sold in New Zealand and Australia
are combination products (multiple drug actives in
same product); combination products are not
available in US.
40. HOW DO COMBINATIONS WORK?
ā¢ Unlike rotating drugs, there is an
additive effect with each drug used
in a combination treatment.
ā¢ By achieving a higher efficacy,
there are fewer resistant worms
that survive treatment.
ā¢ The sooner you start using
combination treatments the better,
as you achieve the greatest
difference in the percentage of
resistant survivors when efficacy of
dewormers is high.
Drug 1 Drug 2 Drug 3 Combo12 Combo123
80% 80% 80% 96.00% 99.20%
90% 90% 90% 99.00% 99.90%
60% 95% 98.00% 98.00%
60% 60% 95% 84.00% 99.20%
99% 99% 99.99% 99.99%
60% 60% 60% 84.00% 93.60%
50% 50% 50% 75.00% 87.50%
40% 40% 40% 64.00% 78.40%
95% 80% 20% 99.00% 99.20%
41. RECOMMENDATIONS FOR USING
COMBINATION TREATMENTS
ā¢ Purchase and administer each dewormer separately in a
separate syringe.
ā¢ Do not mix dewormers. They are not chemically
compatible. Only veterinarians have the right to compound
medications.
ā¢ Administer each dewormer at full dose based on an
accurate weight.
ā¢ Can give one drug immediately after the other.
ā¢ Observe withdrawal period of drug with longest withdrawal
period
42. RECOMMENDATIONS FOR USING
DEWORMERS IN COMBINATION
ValbazenĀ® CydectinĀ® ProhibitĀ®*
Goats 4 ml/50 lbs.
[9 days meat]
[7 days milk]
9 ml/50 lbs.
[17 days meat]
[8 days milk]
Depends on dilution
[4 days meat]
[3 days milk]
https://www.wormx.info/dewormers
46. WHAT ARE COPPER OXIDE WIRE
PARTICLES (COWPS)?
ā¢ Tiny metal rods of copper oxide
(Cu2O).
ā¢ Poorly absorbed, slow release form of
copper versus copper sulfate which is
very absorbable; therefore, greater
potential for toxicity (especially in
sheep).
ā¢ Has been shown to reduce barber pole
worm infections in sheep and goats.
ā¢ Available as copper supplement
(different brands) for cattle (12.5 and
25 g) and goats (2 and 4 g). https://www.wormx.info/copper-oxide-wire-particles
47. COPPER BASICS
ā¢ Goats require more copper than sheep in their
diets and are less susceptible to copper toxicity.
ā¢ Copper metabolism is very complicated, with
several antagonists (interactions), including
molybdenum, sulfur, zinc, cadmium, and iron.
ā¢ Copper absorption is more important than copper
concentration in diet.
ā¢ Copper requirements have been set at 15, 20, and
25 ppm for lactating, mature, and growing goats
respectively [NRC, 2007].
ā¢ The maximum tolerable amount is unknown for
goats.
48. YOU CAN ASSESS THE
COPPER STATUS OF
YOUR HERD
ā¢ Copper toxicity is less likely in goats, but it
can occur, as can a copper deficiency.
ā¢ Blood copper levels can be misleading
ā¢ Excess copper accumulates in liver.
ā¢ Collect liver and kidney samples for
testing.
ā¢ Frozen or chilled samples can be sent to
Michigan State University for testing.
https://www.animalhealth.msu.edu/
52. NEMATODE TRAPPING FUNGUS
DUDDINGTONIA FLAGRANS
ā¢ Duddingtonia flagrans is a
nematophagous fungus, meaning that it
traps, paralyzes, and consumes
parasites.
ā¢ Non-chemical, biological control of the
free-living stage of nematode parasites.
ā¢ Substantially reduces number of infective
worm larvae, including multi-resistant
larvae.
ā¢ Is fed to grazing animals. Spores resist
digestion. No effect on host animal.
Passes through into manure.
ā¢ Reduces amount of reinfection from
contaminated pasture. Interrupts of life
www.duddingtonia.co
m
53. USING FUNGUS TO CONTROL PARASITES
ā¢ Not commercially available. Not yet.
ā¢ Dr. Jim Miller from Louisiana State
University (retired) has been told that
product (fungus) should be available
sometime early 2018.
ā¢ Will need to feed every day to maintain
effect.
ā¢ Cost may be issue.
ā¢ Greatest application is probably zoo
animals.
55. QUALITATIVE
ā¢ Positive or negative. Yes or no. - or +
ā¢ Mix feces with flotation solution.
Place cover slip on meniscus. Put on
slide.
ā¢ Estimates number of eggs in a fresh sample
of manure: eggs per gram of feces (EPG).
ā¢ Mix known amount of feces (2-4 g) with
known amount of flotation solution (26-28
ml)
ā¢ Fill chambers of McMaster slide.
QUANTITATIVE
FECAL EGG COUNTS (FECS)
ā¢ You can learn to do your own
fecals or send sample to a
parasitology lab.
ā¢ Microscope (100x)
Mechanical stage helpful
ā¢ McMaster egg counting slide
ā¢ Homemade flotation solution
56. THREE PRIMARY USES OF
FECAL EGG COUNTS
1. Determine treatment efficacy by comparing before and
after fecal egg counts from a group of animals (~n=15)
ā¢ Determine drug resistance on your farm
ā¢ Determine efficacy of alternative treatment(s)
2. Monitor pasture contamination
ā¢ How fast is pasture contamination building up?
ā¢ Determine when to move animals
3. Identify resistant and susceptible animals
ā¢ Differentiate between resistance and resilience
ā¢ Need sufficient parasite challenge to get data separation (at
least 500 epg group average, 1000 epg better)
By
themselves,
fecal egg
counts are not
a good
diagnostic tool
for making
individual
deworming
decisions.
57. SUSAN SCHOENIAN
S H E E P & G O AT S P E C I A L I S T
U N I V E R S I T Y O F M A RY L A N D E X T E N S I O N
S S C H O E N @ U M D . E D U ā ( 3 0 1 ) 4 3 2 - 2 7 6 7
X 3 4 3
S H E E PA N D G O AT. C O M ā W O R M X . I N F O
Thank you for your attention.
Questions?
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