This document provides information on proper deworming practices for small ruminants. It discusses the classes of dewormers approved for use in sheep and goats, as well as extra-label dewormers. The goals of deworming and environmental considerations are covered. Targeted selective treatment is recommended over whole flock treatments to reduce dewormer resistance. Combination dewormer treatments and non-drug options like copper oxide wire particles are also discussed.

1. Dewormingright
SUSAN SCHOENIAN
Sheep & Goat Specialist
University of Maryland Extension
sschoen@umd.edu | wormx.info | sheepandgoat.com

2. Deworming
• Dewormers are a valuable,but
limited resource.
• Our goalshould be to minimize their
use by relying on other strategies to
control internal parasitism in our
flocks/herds, such as pasture/grazing
management and genetic selection.
• However, when dewormingis required
it should be done right.

3. Goalsofdeworming
• Therapeutic, not prophylactic.
• Treat clinically-parasitized
animals to save their lives,
improve their welfare, and reduce
production losses.
• Need to do so in a manner that
minimizes thedevelopmentof
resistantworms.

4. Dewormers 101

5. Whatisadewormer?
• Drug that kills or expels parasitic
worms by starving or paralyzing
them.
• Must be selectively toxic to the
worm(s) without harming the host.
• Today’s dewormers are muchsafer
and more powerful than older
drugs or old-time remedies.
• Also called anthelmintics.

6. ThreedewormerclassesforsmallruminantsinUSA
Thereiscross-resistanceamongdrugsinthesamegroupduetosimilarmodeofaction.
1
Benzimidazoles (white)
2
Macrocylic lactones
3
Thiabendazole – TBZ®
Fenbendazole - Safe-Guard®,
Panacur®
Albendazole - Valbazen®
Oxyfendazole - Synanthic®
Avermectins
Ivermectin - Ivomec®
Doramectin - Dectomax®
Eprinomectin - Eprinex®
Milbimycins
Moxidectin - Cydectin®, Quest®
Imidazothiaoles (clear)
Levamisole
Prohibit®, Leva-Med®
Tetrahydropyrimidines
Morantel tartrate - Rumatel®
Goat Dewormer, GoatCare, Positive Pellet
1960’s 1980-1990’s 1960’s

7. DewormersFDA-approvedforsheep
1
Benzimidazoles
Valbazen®
2 Macrocyliclactones 3
IMID/TETR
Prohibit®,Leva-
Med®
Avermectins
Ivomec®
Milbimycins
Cydectin®
Adult worms    
Immatureworms (L4)   
Variable
Hypobiotic larvae   
Lung worms    
Tapeworms segments
Liver flukes adult
Coccidia
External parasites  
Persistent activity 
Perlabel Valbazen® Ivomec® Cydectin® Prohibit®,Leva-
Med®
Dosage 3 ml/100 lbs. 3 ml/26 lbs. 1 ml/11 lbs. Depends on dilution

8. 1 Benzimidazoles 3 IMID/TETR
Safe-Guard® Valbazen® Moranteltartrate
Adult worms   
Immatureworms (L4)  
Hypobiotic larvae  
Lungworms  
Tapeworms not labeled 
Liver flukes adult
Coccidia
External parasites
Per label Safe-Guard® Valbazen® Morantel tartrate
Dosage per 50lbs. 1.2 ml 2 ml Depends on product
Meat withdrawal 6 days 7 days 30days
Milk withdrawal NA NA 0 days
DewormersFDA-approvedforgoats

9. 1 Benzimidazoles 2 Macrocyliclactones 3 IMID/TETR
Safe-Guard® Valbazen® Ivomec® Cydectin® Prohibit®,Leva-Med®
Adult worms     
Immatureworms (L4)    
Variable
Hypobiotic larvae    
Lung worms     
Tape worms segments segments
Adult liver flukes adults
Coccidia
External parasites  
Persistent activity 
PerACSRPC(wormx.info) Safe-Guard® Valbazen® Ivomec® Cydectin® Prohibit®,Leva-Med®
Dosage per 50lbs. 2.3 ml 4 ml 12ml 9 ml Depends on dilution
Meat withdrawal 16days 9 days 14days 17days 4 days
Milk withdrawal 4days 7days 9days 8days 3days
Extra-labeldewormersforgoats

10. 1 Benzimidazoles 2 Macrocyliclactones 3 IMID/TETR
Safe-Guard® Valbazen® Ivomec® Cydectin® Prohibit®,Leva-Med®
Adult worms     
Immatureworms (L4)    
Variable
Hypobiotic larvae    
Lung worms     
Tape worms segments segments
Adult liver flukes adults
Coccidia
External parasites  
Persistent activity 
PerACSRPC(wormx.info) Safe-Guard® Valbazen® Ivomec® Cydectin® Prohibit®,Leva-Med®
Dosage per 50lbs. 4.5 4.0 11.4 9.0 Depends on dilution
Extra-labeldewormersforcamelids

11. Safety of dewormers
Dew o rmer
Label
Restric tio ns
A ppro x. safety m argins
Sheep G o a t
Fenbendazole
Safe-Guard®suspension
500 NA
Albendazole
Valbazen®oralsuspension
Pregnancy
First 30days
20 NA
Ivermectin
Ivomec® oraldrench
Otheranimals 30 NA
Moxidectin
Cydectin®oraldrench
>4 monthsofage
Otheranimals
5 NA
Levamisole
Prohibit®drench powder
3 4
Moranteltartrate 20 NA
Human safety: avoid skin contact, wash hands after use
Various sources,
including
parasitipedia.net

12. Environmentalconsiderations
Properdisposal
• Preferablybyuse.
• In a sealedcontainer.
• At approvedlandfillor
byincineration.
• Outofand away from
waterways.
• Whenused correctly,mostofthe dewormers
havea low potentialfor environmental
pollution.
• Macrocycliclactones (endectocides)may
adverselyaffectfishand certainaquatic
species,bedetrimentalto dungbeetles,and
reduceinsectdiversity.
• However,MLs havereducedthe useof much
moretoxicchemicals.

13. How to reduce efficacy of dewormers
• Use past expiration dates.
• Store in open containers.
• Too much exposure to light.
• Store in extreme heat or in freezing
temperatures.
• Store where there is extreme temperature
variation.
• Allow contamination of drench solution.
• Mix with other product(s) before
administration.

14. Dewormer resistance

15. Whatis dewormer resistance?
• Heritable ability of a worm to
survive a dose of dewormer that
should have killed it.
• Exists in a population of worms if
more than 5% of worms survive
treatment.
• Resistant genes are passed onto
the next generation of worms.

16. Dewormerresistance
• May not be noticed untilmore
than50% of worms survive
treatment, and treatmentfails to
alleviateclinical disease.
• Resistanceis generally thought
to be permanent.
• Resistanceis different in
levamisole (autosomal
recessive).

17. StateofdewormerresistanceinUSA
• Worms have developed
varying degrees of resistance
to all dewormers and
dewormer classes.
• Resistance varies by
geographic region and
individual farm.
• Many farms have resistance to
multiple drugs.
• The only way to know which
drugs work on your farm is to
test.
0
10
20
30
40
50
60
70
80
90
100
Benzimidazoles Ivermectin Moxidectin Levamisole All drugs
Percent farms with anthelmintic resistance (<
95% FECR)
2008-2009 - Mid-Atlantic farms 2016-2017 - MD, VA & GA farms

18. Twowaystotestfordewormerresistance
Fecal egg count reduction test
• Compare before and after fecal egg counts
(before treatment and 10-14 days later).
• Use individual or pooled samples from at least 10
animals for each dewormer you want to test.
• Need a lot of animals to test all drugs.
• Minimum FEC of 250 EPG.
• Determines percent fecal egg count reduction
• Cost varies. Can learn to do yourself.
DrenchRite® larval development assay
• Lab test that determines resistance to all dewormer
groups simultaneously from a single pooled fecal
sample from at least 8 animals.
• Minimum FEC of 500 EPG.
• Reports resistance, suspected resistance, and
susceptibility (detects resistance sooner).
• Identifies species of parasites from hatched larvae.
• University of Georgia is only place that does test in
North America (~$500 per sample)
Note: New protocols arebeing developed forthe fecal egg count reduction test,
which has beenthe “gold standard” for determining dewormer resistance.

19. Practiceswhichacceleratedewormerresistance
• Frequent deworming
• Whole flock/herd treatments
• Calendar-based treatments
• Treat and move (to clean pasture)
• Underdosing
• Depositing drug in mouth instead of body cavity.
• Persistent-activitydewormers
• Pouring on dewormers
• Injecting dewormers
• Use of expired dewormers
• Improper storage of dewormers

20. Proper use of dewormers

22. Targeted Selective Treatment (TST)

23. Targetedselectivetreatment(TST)
• Only dewormingthoseanimalswhich
requiretreatmentor wouldbenefitmost
from treatment.
• Slows dewormerresistanceby reducing
numberoftreatments andincreasing
refugia.
• Refugia are worms thathavenotbeen
exposedtodewormer(s).
• TST alsohelpsto identifyanimalswhich
are more resistantandresilientto worms
(and viceversa).
Refugiais nowthe primarystrategy
formaintainingdewormereffectiveness.

24. Toolsfortargetedselectivetreatment(TST)
For chute-sidedecision-making
1. FAMACHA©eye
anemia system
2. Bodyconditionscore
3. FivePointCheck©
4. Performancefactors
5. Other combinedTST

25. FAMACHA©eyeanemiasystem
• Color eye chart that is used to determine level of
anemia in animal;thus, need for deworming.
• Anemia is primary symptom of barber pole worm
(Haemonchuscontortus) infection.
• Trainingis required to purchase a FAMACHA© card.
Due to Covid 19, some universitiesare now offering
online FAMACHA© certification (www.wormx.info/
workshops). Online certification has been available
via University of Rhode Island for several years.FAMACHA© estimates PCV.

26. FAMACHA©EyeAnemiaSystem
Clinical
Category
Eye Lid
Color
Packed Cell
Volume/PCV
Treatment
recommendation
1 Red > 28 No
2 Red-Pink 23-27 No
3 Pink 18-22 ?
4 Pink-White 13-17 Yes
5 White < 12 Yes
COVER
PUSH
PULL
POP

27. Bodyconditionscore(BCS)
• Bodyconditionscore(BCS) is a measureof
therelativefatnessof ananimal.
• Low bodyconditionscore(<2)is indicative
ofa nutritionissueandsuchanimalsare
moreproneto parasiticinfection.
• Variousstudieshaveshownbodycondition
scoreto bea reliableindicatorofinternal
parasitismin adult animals.
• LeavingfemaleswithhigherBCS (>3)
untreatedcanhelpto maintainrefugia.
Body condition scoresrangefrom 1 to 5.

28. FivePointCheck© 5.©
• ExtensionofFAMACHA©system,whichisonlyusefulfor blood-feedingparasites.
• Usesfivecheck pointsonthe animal’sbodyto make dewormingdecisionsfor all parasites
thatcommonlyaffectsmallruminants.Alsousefulfor determiningneed to deworm
FAMACHA©3’s.
1. Eye(FAMACHA©score
2. Back (bodyconditionscore)
3. Tail(dagscore,fecalsoiling,scours)
4. Jaw (bottlejaw)
5. Nose(clear nasaldischarge)
Coat condition(goats)

29. Performanceasadewormingcriteria
• Growthperformance
Deworm anyanimalwhichfailsto
reachperformancetarget (ADG)
Example:theHappyFactor™
• Milk production
Deworm higherproducing
dairyfemales
• Numberof offspring
Deworm femaleswith 3 or
moreoffspring.

30. Periparturient females
Any one
• FAMACHA© > 4
• BCS < 2
• > 3 offspring
• Yearlings,firsttime fresheners
Growing lambs/kids
FAMACHA© > 3
+ ADG (performance target varies)
Ewes/does
FAMACHA > 4
+ BCS < 2.5
+ FEC (threshold varies)

31. Whataboutfecaleggcounts(FEC)?
• Fecal exams are NOT a reliable way to diagnose
parasitic disease in individual animals; it is not their
intended purpose.
• There are no widely-accepted FEC thresholds for
treatment.
• While generally predictive, FEC is not always a good
measure of the worm burden an animal is carrying.
Correlations between FEC and FAMACHA© are not
always high.
• Instead, use FEC to 1) determine efficacy of
dewormers, 2) monitor pasture contamination, and
3) identify more resistant (or susceptible) animals.

32. Combination treatments

33. Combination treatments
• It is now recommended that clinically-
parasitized animalsbe given combination
treatments.
• A combination treatment is when you give
more thanone dewormer (drug active) to kill
the same worms.
• The purpose of combination treatments is to
killas many worms as possible.
• Worms not killed by the first drug can be
killed by the second (and third).

34. Recommendations for combination treatments
• Give most potent drug from each dewormer class.
albendazole+ moxidectin+ levamisole
(Valbazen® + Cydectin® + Prohibit®)
• Give full dose of each dewormer.
• Do not mix dewormers; they are not chemically
compatible.
• Use separate syringe/drench gun for each drug
(ideally).Combination dewormers are
not available in USA.

35. Recommendations for combination treatments
• Give dewormers sequentially, one
after theother to get additive effect.
• Observe withdrawal period of
dewormer with longestwithdrawal.
• ONLY give combinationtreatments to
clinically-parasitizedanimals, as
determinedby TST criteria. Do not give combination
treatments to all animals!

36. Non-drug options for “deworming”

37. Copperoxidewireparticles(COWP)
• Tiny metal rods of copper oxide.
• Slow release, poorly absorbed form of copper.
• Proven to be effective againstbarber pole
worms (Haemonchuscontortus).
• May increaseefficacy of treatment when given
in combination with a dewormer, e.g. COWP +
Valbazen® (USDA, 2020).
• May be approved by some organic certifiers.

38. DewormingwithCOWP
• Availableas coppersupplements (boluses)
for cattle(12.5and 25 g) andgoats (2 and 4
g).
• Repackage larger bolusesintosmallerdoses
for dewormingsheepandgoats.
• Give smallesteffectivedose,usually0.5-1g
for lambs/kidsand 1-2 g for matureanimals.
• Selectivelytreat accordingto TSTguidelines.
Usesafely. Monitor copperstatus
(especially with sheep).

39. Othernon-drugoptionsfordeworming
• Hundreds of “natural” things are said to have
deworming properties.
• With the exception of COWP, none have been proven
to kill worms safely, effectively,and consistently.
• However,if a naturalremedyimproves host immunity
or disrupts the free-livingstage of the worm,it could
reduce the number of animals that need treatedwith
drugs (Examples: sericealespedeza, BioWorma®).
• If you choose to use naturalremedies, be sure to keep
monitoring animals for signs of parasitismand give
them drugs (when necessary) to save their lives.
Thereisnoscientific evidence that
DEis effective asadewormer.

40. Treatment of other parasites

41. Treatingmeningealworm(deer,brainworm)
• Thereare noFDA-approvedtreatment
protocolsfor meningealworm insmall
ruminants.
• Alltreatmentprotocolsare extra label
andrequireveterinaryapproval.
• Treatmentusuallyinvolveshigh-dose,multiday
dosingwitha dewormer (fenbendazole)
and anti-inflammatorydrug(s).
• CornellUniversityhas evaluatedtreatmentprotocolsfor sheepand goats.
http://blogs.cornell.edu/smallruminantparasites/chemical-treatment-protocols/
Parelaphostrongylustenuis_

42. Treatmentfortapeworms
• Tapewormsare usually non-pathogenic;most
studiesshownobenefitto treating(lambs).
• Albendazole(Valbazen®)is the onlydewormer
labeledfor theremovaloftapeworms(segments)
insmallruminants(and insheeponly).
• Fenbendazole(Safe-Guard®)is notlabeledfor
tapewormremoval,butis effectiveat higherdoses.
• Praziquantel isthe drugof choicefor tapewormremoval. It’susein small ruminantsis
extra-label.It is availableinseveralhorsepastewormers (e.g.Quest®Plus).
Monieziaexpansa_

43. Treatmentofliverflukes
• Liver flukesare onlyproblematicincertain
areas of theUSA (Northwest,GulfStates).
• Albendazole(Valbazen®)is theonly
dewormerlabeledfor theremovalofliver
flukes(adultflukesonly)insheep/goats.
• Ivomec®Plus(ivermectin+ clorsulon)is an
extra labeloptionfor tapewormremovalin
smallruminants.
• Timingoftreatmentis important:consultyour
veterinarian. Fasciolahepatica_

44. Extra label drug use

45. ExtralabeldruguseintheUSA
• Only a licensed veterinarian has the legal
right to use or prescribe a drug extra label.
• Extralabel is when you use a drug in any
manner that is not listed on its label. This
includes different species, dosage, frequency,
or route of administration.
• Not all drugs can be used extra label; there
are specific requirements governing the
extra label use of drugs.
“Off-label”is notalegal termin USA.

46. ExtralabeldruguseintheUSA
• Extralabeldrug use is usually required to
dewormgoats,as the moreeffective
dewormersare not FDA-approvedfor goats.
• Extralabeldrug use is required to deworm
camelids,as no dewormersare FDA-
approved for camelids.
• To use drugs extralabel, you need to have a
valid veterinarian-client-patientrelationship
(VCPR).Ivomec® drenchis onlyapprovedforsheep.

47. SUSAN SCHOENIAN
Sheep & Goat Specialist
University of Maryland Extension
sschoen@umd.edu | wormx.info | sheepandgoat.com
Thank you. Questions?