Presentation for 2019 Delmarva Small Ruminant Conference All Worms All Day. December 7, 2019. Lincoln Memorial University, Ewing, Virginia.

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

2. Presentation topics
Drugs
 Anthelmintics 101
 Anthelmintic resistance
 Testing for resistance
 Natural treatments
Using drugs
 Targeted selective
treatment (TST)
 Combination treatments
 Treatment and prevention of coccidiosis
 Tapeworm removal
 Treatment of meningeal worm
 Veterinary-Patient-Client Relationship

3. Dewormers
(Anthelmintics)
101

4. What is a dewormer?
(also called anthelmintic)
 A drug that expels worms from the body by either stunning
them or starving them to death.
 Needs to be selectively toxic to the worm, but not toxic to
the host.
 Can be broad spectrum (e.g. Valbazen®) or target a
specific worm (e.g. praziquantel; Vx).
 Can contain one drug or more than one drug (active):
combination dewormers (QuestPlus®; equine, Vx).
Introduced in
early 80s.

5. Three dewormer classes
for sheep and goats
1) Benzimidazoles (BZD)
white dewormers
2) Macrocylic lactones (ML)
a) Avermectins
b) Milbimycins
3) Membrane depolarizing class
Nicotinic agonists
• Dewormers are separated into classes
based on similar chemical structure and
mode of action.
• Cross-resistance usually develops among
drugs in the same class.

6. [1] Benzimidazoles (BZD)
Fenbendazole
SafeGuard® *
 Labeled dose
ineffective.
 Effective against
tapeworms at
higher dosage (Vx).
 Drug of choice for
meningeal worm.
Albendazole
Valbazen® **
 More potent than fenbendazole
 Effective against tapeworms
(heads + segments)
 Effective against adult liver flukes
 Pregnancy restriction
First 30 days 
*FDA-approved for goats
**FDA-approved for sheep
and liver fluke control in goats

7. [2] Macrocylic Lactones
[A] Avermectins *
1) Ivermectin
Ivomec®*
2) Doramectin
Dectomax®
3) Eprinomectin
Eprinex®
[B] Milbimycin
1) Moxidectin
Cydectin®*, Quest®
*FDA-approved for sheep
 Persistent activity
 Effective against external parasites (Ivomec®: nasal bots)
 Avermectins more effective against external parasites
 Milbimycins more effective against internal parasites.
 Avermectins are harmful to dung beetles.

8. [3] Membrane cell depolarizers
Levamisole*
Prohibit®
Leva-Med®
 Usually most effective Tx
 Less effective against larvae [?]
 Shortest withdrawal period
 Lowest margin of safety (~3x)
 Comes in powder that you have
to dissolve in water.
Morantel tartrate**
Rumatel®
Mor-Max®
Positive Pellet®
 Only kills adult worms
 Top-dress or mix in feed
 30 day meat withdrawal
0 day milk withdrawal
*FDA-approved for sheep
**FDA-approved for goats

9. What is anthelmintic resistance?
 Genetic ability of a worm to survive a dose of dewormer
that would otherwise be effective.
 Worms that survive treatment carry resistant genes
which are passed onto the next generation (of worms).
 We select for resistance when we expose the worm
population to dewormers.
 An effective treatment should reduce fecal egg count (FEC) by 95% or more;
otherwise resistance is present.
 Eventually, the percentage of resistant worms is so high that the dewormer is no
longer effective as the sole treatment.

10. What practices have helped to
accelerate anthelmintic resistance?
 Frequent treatments
 Whole flock or herd treatments
 Underdosing
 Treating and moving animals to a clean pasture
 Rotating dewormers
 Depositing drug in mouth instead of over back of tongue
 Persistent activity dewormers
 Injecting dewormers
 Pouring on dewormers
 Feeding dewormer to a group of animals instead of individually
 Feeding dewormer in free choice salt or mineral
 Improper storage of dewormers

12. How prevalent is anthelmintic
resistance in the Southeast?
0
20
40
60
80
100
Benzimidazoles Ivermectin Levamisole Moxidectin
Maryland Virginia Georgia
2016-2017
ASI Let’s Grow
Percent sheep farms
(n=30) with resistance
to dewormer classes

13. How do you determine dewormer
resistance?
Fecal egg count
reduction test (FECRT)
 Compare before and
after deworming fecal
egg counts from
individual or pooled
fecal samples from
same ~15 animals.
DrenchRite® larval
development assay
 Lab test that
determines
resistance to all
anthelmintic classes
from a single pooled
fecal sample.
 University of Georgia

14. Natural
Treatments

15. Nematode-trapping fungus
 BioWorma® is a new product that contains a
fungus (Duddingtonia flagrans) that traps and kills
roundworm larvae in the manure of livestock.
 It needs to be fed daily for 60 to120 days during
peak worm transmission season, to highest risk
animals (periparturient females, lambs/kids).
 It is a feed-through product, with no effect in the
animal or on existing pasture contamination.
 Natural biological control
duddingtonia.com
Can’t get wet or be
made into a pellet.

16. Two products are available.
[1 ] BioWorma®
 Contains 34.6%
fungus
 Due to EPA
restrictions,
distribution is limited
to veterinarians, feed
mills, and premixers.
[2] Livamol® with
BioWorma®
 Nutritional
supplement
containing 2.2%
fungus
 Available over-
the-counter (OTC)
Livamol® + BioWorma®
40 to 60 ¢ per day
For 100-lb. animal
(Premier 1 Supplies, Iowa)

17. Copper oxide wire particles
(COWP)
 Tiny needles of copper oxide
 Slow release form of copper
 Poorly-absorbed form of copper
 Has been shown to reduce barber pole worm
(Haemonchus contortus) infections in sheep
and goats.
 Available as a copper supplement for cattle
(12.5, 25 g) and goats (2, 4 g).
Only non-synthetic
compound with proven,
consistent efficacy
against worms.

18. How to use COWP as a dewormer
 Always use lowest dose possible to achieve deworming
effect.
 Dosage is based on age, not weight
0.5 to 1 g for lambs and kids
1 to 2 g for mature animals
 Repackage cattle and goat boluses into smaller doses
 Can be challenging to administer; use plastic balling
gun, pet piller, or small PVC pipe with wooden dowel.

19. Be safe using COWP,
especially with sheep
 Before using, check copper status of flock/herd by
submitting livers (or kidneys) to diagnostic lab for
mineral profile.
 Selectively treat according to TST criteria.
 Minimize number of treatments given to same animal.
 Periodically, re-check copper status of flock/herd.

20. Targeted Selective
Treatment
(TST)

21. What is targeted selective
treatment (TST)?
 Deworming only those animals that require
treatment or would benefit most from
treatment.
 TST is the recommended strategy for controlling
internal parasites in small ruminants.
 TST slows anthelmintic resistance by reducing
the number of treatments, which increases
refugia.

22. What are refugia?
 Refugia are worms which have not been exposed
to the dewormer(s). They exist in animal and on
pasture.
 The goal is to dilute the resistant worms on a
farm so that a sufficient portion of the worm
population remains susceptible to treatment.
 Refugia are needed to slow down the
development of resistant worms.

23. How to maintain refugia
 Reduce number of treatments
 Do not treat everyone
 Leave at least 10% (ideally 15-20%
or more) of animals untreated.
 Adults animals in good body condition are the
best animals to leave untreated to achieve
refugia.

24. Tools for targeted selective
treatment (TST)
 FAMACHA© eye anemia system
 Body condition score (BCS)
 Five Point Check®
 Performance indicators
 Other TST strategies

25. FAMACHA©
eye anemia
system

26. FAMACHA© eye anemia system
 Color eye chart that estimates the level of anemia
(blood loss) in the animal.
 Anemia is the primary symptom of barber pole worm
(Haemonchus contortus) infection.
 Anemia is measured by packed cell volume (PCV); the
portion (%) of red blood cells in whole blood (hematocrit).
 While there are other causes of anemia, the barber pole
worm is by far the most common.
Developed almost 30
years ago by South
African researchers.
Introduced to US in 2002.

27. Using FAMACHA©
 Get required training: in-person or online
 Use proper technique
COVER-PUSH-PULL-POP
 Score under natural lighting
 Check at appropriate intervals
Every 1-3 weeks during peak transmission season
 Give effective dewormer(s) (and supportive therapy, as
necessary) to clinically-parasitized animals.
 Replace card, as necessary.

28. Treatment Recommendations
 Don’t treat 1s and 2s unless there are other signs of
internal parasitism.
 Always treat 4s and 5s with effective dewormer(s).
 Give consideration to treating 3s
 Periparturient females
Lambs and kids
 All goats
 Use Five Point Check© and/or other parameters to decide whether to deworm 3’s.
 Deworm 3s if scores are tending higher and/or more than 10% of animals are
FAMACHA© 4-5.

29. Body condition
score (BCS)

30. Body condition score (BCS)
 BCS can be a reliable indicator of internal parasitism in
adult animals (not so much in growing animals).
 Low BCS (≤2) is indicative of a nutrition issue.
 Animals with low BCS are more prone to parasitic
infection
 Animals with low BCS and on low plane of nutrition are
less able to cope with parasites.
 BCS is part of the Five Point Check©.

31. Body condition score (BCS)
 A measure of the relative fatness of an animal.
 It is necessary to touch the animal to determine BCS.
 Determined by feeling for fat and muscle over the
spine, ribs, and loin.
 Small ruminants are rated on a scale of 1 to 5, with 1
being emaciated, 3 being average, and 5 being obese
(half scores are used).
 BCS differs among animal type.

32. Five Point
Check®
5 . 

33. Five Point Check© (5.)
 An extension of the FAMACHA© system which only assesses
damage by blood-feeding parasites, primarily barber pole worm.
 Adds criteria for determining need to deworm for all parasites,
including those that cause diarrhea (scours) and infect
nasal cavities.
 Five check points: 1) eye, 2) nose, 3) jaw, 4) back, and 5) tail.
 Coat condition is sometimes used as a checkpoint with goats.
 Emphasizes importance of using multiple criteria to make
deworming decisions.
 Especially useful for making deworming decisions for
FAMACHA© 3s.
Developed by
same South
African researchers
who developed
FAMACHA©

35. Other tools or
strategies for
targeted selective
treatment

36. Performance-based criteria
 Performance can be used to make deworming decisions.
 The Happy Factor™ model predicts a target weight for
lambs. Those not achieving the predicted level of
performance are dewormed.
 High producing dairy goats or those in their first lactation
can be targeted for treatment.
 Litter size can be used as a criteria for deworming (or
not). Example: don’t treat females with singles, but
treat females with 3 or more offspring.

37. Fecal egg count (FEC)
 FEC is a deworming criteria for other livestock and in
large flocks/herds where individual assessment is not
practical.
 Thresholds for treatment vary; some animals should
be left untreated to maintain refugia.
 By itself, FEC is not a good diagnostic tool for
determining the need to treat an individual animal.
 FEC is best when combined with other criteria, such
as FAMACHA© and body condition score.

38. Other combined TST
 FAMACHA© + gain
 BCS + FAMACHA© + FEC
 Age + FAMACHA© + BCS + #offspring
TST can be effective, so long as accurate indicators are
used to identify animals that need treatment.

39. Combination
treatments

40. What is a combination treatment?
 A combination treatment is when you give more than one
dewormer to kill the same worm species.
 The purpose is to kill as many resistant worms as possible.
 Combination treatments have an additive effect on the
worm population; worms that survive the first drug can be
kill by the second (or third).
 Combination treatments only work when the drugs in the
combination still have some efficacy.

41. Recommendations for giving
combination treatments
 Combination drugs are currently not available in US.
 You must purchase and administer each drug separately.
 Do not mix the drugs.
 They are not chemically compatible.
 It is illegal to compound medications.
 Ideally, use a separate syringe for each drug.

42. Recommendations for giving
combination treatments
 Give the most potent drug from each class
albendazole (Valbazen®) +
moxidectin (Cydectin®) +
levamisole (Prohibit®, LevaMed®)
 Give full recommended dose of each drug, based on
accurate weight.
 Administer sequentially, one after the other.
 Observe withdrawal period of drug with longest withdrawal
(usually Cydectin®).

43. Recommendations for giving
combination treatments
 Only give combination treatment to clinically-parasitized
animals, as determined by TST criteria.
 Do not give combination treatments to all animals
in a management group.
 Failure to maintain refugia will result in worms that are
resistant to multiple drugs.
 There is an FDA-approved drug in each class for sheep.
 For goats and camelids, combination treatments using recommended drugs
require extra label drug use (ELDU), as prescribed by a veterinarian (Rx).

44. Dewormer + COWP
 There is some evidence that copper oxide wire particles
(COWP) can be used in conjunction with a dewormer to
improve efficacy of treatment.
Treatment
(10-23 lambs per Tx group)
Efficacy
(%FECR)
No treatment (control) Increase
Valbazen® (3 ml/50 lbs.) 20%
COWP (2 g, Ultracruz™) 58%
COWP (2 g, Copasure®) 12%
Valbazen® + COWP 99%
Burke, USDA-ARS, Booneville, Arkansas
http://www.wormx.info/cowpcombo

45. Prevention and
treatment of
coccidiosis

46. Drugs for coccidia
(Eimeria spp.)
Treatment
 No drugs are FDA-
approved for treatment
of coccidiosis in sheep
and goats.
 All drugs are extra label
or must be obtained
from a veterinarian.
Prevention
 There are several
FDA-approved
coccidiostats that
can be put in the feed
or mineral to prevent
coccidiosis in sheep
and goats.
Dewormers
have no effect
on coccidiosis.

47. Drugs for coccidia
(Eimeria spp.)
Treatment
 Amprolium
(OTC, Rx)
Corid®
 Sulfa antibiotics
(Rx)
Di-Methox®
Sulmet®
Albon®
Prevention
 Amprolium (Corid®) [Rx]
(better for treatment)
 Ionophores
 Lasalocid (Bovatec®)*
 Monensin (Rumensin®)**
 Non-antibiotic
 Decoquinate
Deccox®* **
* FDA-approved for sheep
** FDA-approved for goats
 Toxic to equines

48. Prevention and treatment of
coccidiosis
Treatment (ELDU, Vx)
 Corid® or Di-Methox® is
usually put in the drinking
water for 5 days.
 Individual drenching of
animals is preferable.
 Corid® inhibits thiamine
production; some risk of
polio with excessive intake.
 Resistance to Corid® is
suspected.
Prevention
 Put coccidiostat in feed
or mineral.
 Timing is everything;
need to feed before risk.
 Dosage is important; animal must
consume enough drug to be effective.
 Feed milk replacer with coccidiostat in it.
 Feed to females in late pregnancy to reduce
shedding of oocysts (Rx)

49. Natural treatments for coccidia
 Sericea lespedeza (AU Grazer pellets) has been
show to reduce fecal oocyst counts and improve
fecal consistency scores in lambs and kids.
 Essential oils (e.g. oregano) have shown promise
as natural coccidiostats for sheep and poultry
(more research is needed).
 Timing and consumption equally important for
natural treatments.

50. Removal of
tapeworms
(Moniezia spp.)

51. Removal of tapeworms
 Specific drugs required
 Valbazen® is FDA-approved for treatment of
tapeworms (in sheep).
 Extra label drug use (ELDU; Vx) is required for tapeworm
removal in goats (with Valbazen® or SafeGuard®)
 Praziquantel is the drug of choice for tapeworms.
 Praziquantel is not FDA-approved for sheep/goats.
 It is available (OTC, Vx) in three combination horse paste
dewormers: Equimax®, Zimecterin®, QuestPlus®
There is little
evidence that
treatment for
tapeworms is
beneficial.

52. Treating
meningeal worm
(P. tenius)

53. Treatment of meningeal worm
3-year study at Cornell University
Research project treatment protocol
Fenbendazole (SafeGuard®)
orally 5 days @ 1.33 cc per 100 lbs. (Vx)
Anti-inflammatory drug for 5 days
Dexamethasone (Rx) or Banamine (Rx)
No benefit to injectable ivermectin (Vx)
http://blogs.cornell.
edu/smallruminantp
arasites/chemical-
treatment-protocols/

54. Veterinary-
Client-Patient
Relationship
(VCPR)

55. Veterinary Client Patient
Relationship (VCPR)
1) The veterinarian has assumed the responsibility for making clinical judgments
regarding the health of the patient and the client has agreed to follow the
veterinarians' instructions.
2) The veterinarian has sufficient knowledge of the patient to initiate at least a general
or preliminary diagnosis of the medical condition of the patient. This means that the
veterinarian is personally acquainted with the keeping and care of the patient by virtue
of a timely examination of the patient by the veterinarian, or medically appropriate
and timely visits by the veterinarian to the operation where the patient is managed.
3) The veterinarian is readily available for follow-up evaluation or has arranged for the
following: veterinary emergency coverage, and continuing care and treatment.
4) The veterinarian provides oversight of treatment, compliance, and outcome.
5) Patient records are maintained.
Source: AVMA
Only a veterinarian
has the legal right
to use or prescribe
drugs extra label.

56. sheepandgoat.com