Presentation for MVMA Mid-Atlantic States Bovine Conference, Hagerstown, MD: March 30- 31, 2017.

1. Current recommendations for
internal parasite control in
small ruminants
SUSAN SCHOENIAN (SHAY-NE-UN)
Sheep & Goat Specialist
University of Maryland Extension
sschoen@umd.edu - sheepandgoat.com - wormx.info

2. Current recommendations for internal
parasite control in small ruminants
Topic outline
 American Consortium for Small
Ruminant Parasite Control
 Background
Problem and parasites
 Anthelmintics and resistance
 Targeted selective treatment (TST)
 Combination treatments

3. American Consortium for Small Ruminant
Parasite Control (ACSRPC)
 Southern Consortium for Small Ruminant Parasite
Control (SCSRPC) was formed in 2003 in
response to the critical state of the small
ruminant industry associated with the emergence
of anthelmintic-resistant worms.
 As membership expanded, the name was
changed to the American Consortium for Small
Ruminant Parasite Control (ACSRPC).
 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 stakeholders in the
small ruminant industry on
the most up-to-date methods
and recommendations for
control of gastrointestinal
nematodes.

4. Our web site: acsrpc.org or wormx.info
 Timely Topics (new article monthly)
 Member profiles and contact info
 Articles
 Journal articles and abstracts
 Teaching materials
 Videos and images
 Conference proceedings
2013 - 10th anniversary conference
2015 - South African Conference
2018 - 15th year anniversary (?)
 List of FAMACHA© instructors
Do you want your name added?
 List of upcoming workshops
Are you conducting a workshop?
Your one-stop information source for internal
parasite control in small ruminants.

5. Gastro-intestinal parasites (GIP)
 Gastro-intestinal parasites (GIP) are the
primary health problem affecting sheep
and goats in warm, moist climates.
 There are many reasons why sheep and
goats are more vulnerable to parasitic
infection than other farm animals.
 Sheep and goats can be infected
simultaneously with many different kinds
of GIP, but two are usually of primary
concern: barber pole worm and coccidia.

6. Risk of parasitic infection varies
Environment
 Geographic region
 Climate
 Season
 Rainfall
 Temperature
 Humidity
 Farm: production practices
 Birthing period
 Grazing practices
 Method of growing/finishing lambs
and kids.
Animal
 Species
Goats generally more susceptible
than sheep
 Breed
Some breeds less susceptible
e.g. hair sheep, Kiko and Spanish
goats
 Age
Young stock most vulnerable
 Production status/level
Periparturient female also more
vulnerable

7. Challenges to controlling internal parasites in
small ruminants
Parasites
 Short, direct life cycles
 Strongyles have ability to go into
hypobiotic (arrested) state and
survive over the winter in the
animal.
 Barber pole worm is a very prolific
egg layer.
 Barber pole worm is one of the
most pathogenic (deadly)
parasites.
Drugs
 No new dewormers in over 20 years.
 New dewormers are not sold in US.
(Zolvix®, Startect®)
 No combination products in US.
 Few FDA-approved dewormers for
goats; ELDU usually required to
effectively treat goats.
 The worms have developed resistance
to all dewormers and dewormer
groups.

8. Gastro-intestinal parasites of small
ruminants
Multi-cellular: Helminths
1. Nematodes
Roundworms
Strongyles
2. Cestodes
Tapeworms
Flatworms
3. Trematodes
Flukes
Single-cell: Protozoa
1. Coccidia
2. Giardia
3. Cryptospordia

9. Nematodes - Roundworms - Strongyles
Primary
1. Haemonchus contortus
Barber pole worm
2. Trichostrongylus spp.
Black scour worm (bankrupt worm)
3. Teladorsagia (Ostertagia)
Brown stomach worm
Other
 Cooperia
small intestinal worm
 Nematodirus
threadneck worm
 Oesaphagostomum
nodule worm
 Bunostomum
Hookworm
 Trichuris ovis
Whipworm
 Strongyloides
Threadworms
 Lungworms
 Parelaphostrongylus tenuis
Meningeal worm
Deer worm, brain worm

10. Gastro-intestinal nematodes (GIN)
roundworms, strongyles
1. Haemonchus contortus
Barber pole worm
2. Trichostrongylus
Black scour worm
3. 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.

11. Clinical signs of infection
Barber pole worm
Haemonchus contortus
 Anemia
Blood and protein loss
Low packed cell volume (PCV)
 Sub-mandibular enema
swelling under jaw
“Bottle jaw”
 Loss of weight and condition
 Scours (diarrhea)
 Weakness
 Anorexia
 Death (often)
 Acute haemonchosis = sudden death
Trichostrongylus spp.
Teladorsagia
 Hypersensitivity of gut
Damage and inflammation of gut
Diarrhea (scours)
 Loss of weight and condition
Slow growth
 Lethargy
 Death (sometimes)
 Additive: usually part of mixed
infections with H. contortus.

12. Meningeal worm (Parelaphostrongylus tenuis)
 Parasite of white tail deer
(non-pathogenic)
 Sheep, goats, and camelids are
abnormal, aberrant hosts for parasite.
 Parasite has indirect life cycle:
snail or slug required as
intermediate host.
 Sheep/goats get infected when they
consume snail, slug, or slime stream
(on vegetation) containing L3 (larvae).
 Larvae travel from intestinal tract
to spinal cord to brain, causing nerve damage and inflammation.

13. Meningeal worm (Parelaphostrongylus tenuis)
 No definitive diagnostic in live animal
 Diagnosis is usually based on clinical signs
and history.
 Parasite is difficult to locate in necropsy.
 Symptoms: lameness, hind end weakness,
gait abnormality, constant itching, paralysis
(extreme) and death (rare).
 Animals typically maintain appetite.
 No proven or FDA-approved treatment.
 Cornell University has been evaluating
treatment protocols and potential for
vaccine.
Cornell University image

14. Treatment protocol for meningeal worm (ELDU, Rx) Cornell
University (14 farms: 38 goats and sheep)
Not pregnant Late Gestation
Fenbendazole (SafeGuard®)
25 mg/kg orally for five days (1 1/3 cc/10 lbs.
[Meat WD: 28 d, goats; 80 d, sheep]
Dexamethasone
0.2 mg/kg IM for first 3 days (½ cc/10 lbs.)
0.1 mg/kg IM for next 2 days (¼ cc/10 lbs.)
Banamine
1.1 mg/kg orally for 5 days
(1 cc/100 lbs.)
Treatment A Treatment B
Ivermectin 1% injectable
0.5 mg /kg SQ for 5 days (¼/10 lbs.)
[Meat WD: 96 d, sheep and goat]
Ivermectin placebo
¼ cc/10 lbs. SQ for 5 days
It is not known if ivermectin improves outcome; however, it increases meat withdrawal to 96 d.
Theoretically, ivermectin cannot pass through the blood-brain barrier.
https://nydairyadmin.cce.cornell.edu/uploads/doc_392.pdf

15. Tapeworms (Moniezia expansa)
 Diagnosed by seeing segments in feces
or passage of worm.
 Only worm that is visible in feces or
outside of animal.
 Parasite has indirect life cycle; pasture
(grass) mite serves as intermediate host.
 Tend to be non-pathogenic;
immunity develops at an early age.
 Almost all research (sheep) shows no
benefit to treating for tapeworms.

16. Tapeworms (Moniezia expansa)
 Heavy infestations
1. Mild unthriftiness and GI disturbances
2. Intestinal blockages (rare)
3. Alter intestinal function/affect gut motility,
predisposition to enterotoxemia (occasional.
 Treatment
 SafeGuard® (2x dose, Rx)
 Valbazen® (Rx, goats)
 Praziquantel [Rx] via Quest Plus®,
Equimax®, or Zimecterin Gold®.
 Sheep and goats can be intermediate hosts
for tapeworms that infect dogs.
Called sheep measles (cysts in meat).

17. Coccidia
Eimeria spp.
 Not all Eimeria spp. are pathogenic
 Eimeria spp. are host-specific
 Coccidia has a more complex life
cycle than roundworms.

18. Coccidiosis
 Most commonly seen in lambs and kids just
before weaning.
 Most common in intensively-managed
operations, but outbreaks can occur in
pasture-rearing environments.
 Most commonly associated with poor hygiene,
wet conditions, overcrowding, and stress.
 Sheep develop strong and lifelong immunity;
coccidiosis is rare in adult sheep.
 Goats don’t develop as strong immunity;
coccidiosis can occur in goats of any age.
 Adults harbor small numbers of coccidia and
are source of infection for their offspring.

19. Signs of coccidia infection
 Diarrhea (scours) – not always
Brown, liquid, foul-smelling
Sometimes containing blood or mucous
 Dirty hocks, tail
 Hollow flanks, hunched up appearance
 Open fleece
 Depressed
 Dehydration
 Anemia
 Death (some cases)
 Fecal oocyst counts not overly reliable as
a diagnostic tool.
Animals that recover may experience more subtle
and long-lasting effects.

20. Coccidiosis
Prevention
 Good hygiene and management
 Coccidiostats in feed or mineral
1. Lasalocid
Bovatec® (sheep, Rx goats)
2. Monensin 
Rumensin® (goats, Rx sheep)
3. Decoquinate (non antibiotic)
Deccox® (sheep, goats)
 Coccidiostats in water
1. Amprolium (Rx, OTC)*
Corid®
2. Sulfa drugs (Rx)*
Di-Methox®
 Natural control
 Sericea lespedeza
 Oregano oil
Treatment
 Amprolium (OTC, Rx)
Corid®
 Sulfa drugs* (Rx)
Di-Methox®
*As part of the new Veterinary Feed
Directive (2017), water-soluble
drugs (e.g. sulfa antibiotics; Di-
Methox®) transitioned from OTC to
Rx.

21. Sericea lespedeza for natural control of
internal parasites
0%
20%
40%
60%
80%
100%
Experiment 1 Experiment 2A Experiment 2B
Percent reduction in egg and oocyst counts (after 7 days)
compared to control diet
EPG OPG
Differences were maintained or increased
throughout trial. In Exp. 2, fecal
consistency scores were lower in goats
fed SL pellets for 4 weeks .
Fort Valley State University: recently weaned bucks were fed SL pellets for 28 days (confinement)
2A: pellets from leaf meal stored 3 years; 2B: pellets from leaf meal stored less than 6 months.

22. Sericea lespedeza for natural control of
internal parasites (lambs)
Experiment 1
 Weaned lambs (n=76)
Naturally infected
Control or SL diet
With or w/o amprolium
 Fecal oocyst counts were
similar between dietary
groups.
 Fecal oocyst counts
declined more rapidly
after weaning in
amprolium-fed lambs.
 Control lambs had higher
fecal scores (more soiling).
Experiment 3
 Lambs (n=24)
Control or SL diet
Innoculated with 50,000
sporulated oocysts.
 Fecal egg and oocyst
counts were reduced in
SL-fed lambs.
Experiment 2
 Twin-bearing ewes
Nursing lambs (n=62
Creep fed
Control or SL diet
30 d before weaning
Weaned to semi-confinement
 Fecal oocyst counts were similar
between dietary groups, but declined
in SL-fed lambs by weaning.
 Dag and fecal scores were lower by
weaning for SL-fed lambs.
 No SL-fed lambs required treatment
compared to 33% of control lambs.

23. Anthelmintics 101
There are only 3 families of drugs.
BENZIMIDAZOLES (BZ)
“white dewormers”
1. Fenbendazole
Safeguard® Panacur®
2. Albendazole
Valbazen®
3. Oxyfendazole
Synanthic®
MACROCYLIC
LACTONES (ML)
1. Avermectins
a) Ivermectin
Ivomec®
Primectin®
Privermectin®
b) Eprinomectin
Eprinex®
c) Doramectin
Dectomax®
2. Milbimycins
a) Moxidectin
Cydectin®
Quest®
NICOTINIC AGONISTS
“cell depolarizers”
1. Imidazothiaoles
a) Levamisole
Prohibit®
Leva-Med®
2. Tetrahydropyrimidines
a) Morantel
Rumatel®
Positive Goat Pellet
Goat dewormer
b) Pyrantel
Strongid®
1 32

24. (1)
Benzimidazoles
(2) Macrocylic lactones (3)
NicotinicsAvermectins Milbimycins
Adult worms    
Immature worms (L4)     -
Hypobiotic larvae     ?
Lung worms     +
Tapeworms 
Liver flukes adult
Coccidia
External parasites  
Persistent activity 
Safety Do not use in first 45
days of pregnancy
++++ ++++ ++
Resistance (in general) ++++ +++ ++ +
FDA-approved Valbazen® Ivomec® Cydectin® Levamisole®
Labeled dosage 3 ml/100 lbs. 3 ml/26 lbs. 1 ml/11 lbs. 2 ml/50 lbs.*
Meat withdrawal 7 days 11 days 7 days 3 days
FDA-approved anthelmintics for sheep
*Concentrated drench: 52 g packet mixed in 17.5 oz. of water

25. (1) Benzimidazoles (3) Nicotinics
SafeGuard® Valbazen® Rumatel®
Adult worms   
Immature worms (L4)  
Hypobiotic larvae  
Lung worms  
Tapeworms not labeled
Liver flukes adult
Coccidia
External parasites
Safety ++++ Do not use first 45 days
of pregnancy
+++
Resistance ++++ n/a ?
Labeled dosage per 100 lbs. 2.3 ml 4 ml 44 g or 0.1 lb.
Meat withdrawal 6 days 7 days 30 days
Milk withdrawal NA NA 0 days
FDA-approved anthelmintics for goats

26. (1) Benzimidazoles (2) Macrocylic lactones (3) Nicotinics
SafeGuard® Valbazen® Ivomec® Cydectin® Prohibit®
Adult worms     
Immature worms (L4)      -
Hypobiotic larvae      ?
Lung worms      +
Tape worms  
Adult liver flukes 
Coccidia
External parasites  
Persistent activity ?
Safety ++++ Restricted use during
early pregnancy
++++ ++++ ++
Resistance ++++ ++++ +++ ++ +
Dosage per 25 lbs. 1.1 ml 2 ml 6 ml 4.5 ml 2.7 ml*
Meat withdrawal 16 days 9 days 14 days 17 days 4 days
Milk withdrawal 4 days 7 days 9 days 8 days 3 days
Extra-label anthelmintics for goats (Rx, ELDU)
Source: ACSRPC (http://www.wormx.info/dewormers) *52 g packet mixed in 1 quart (943 ml) of water

27. Anthelmintic (dewormer) resistance
 Worms have developed varying degrees of resistance to all
dewormers and dewormer groups; there is cross resistance
to dewormers in same group.
 Resistance varies by geographic location and individual
farm and is affected by prior dewormer use.
 Resistant worms pass their resistant genes onto the next
generation or worms.
 Resistance differs in levamisole
(homozygous recessive=resistance)
 Resistance is/was inevitable; no treatment will kill 100% of
worms.
 Resistance is defined as failure to reduce fecal egg counts
by 95% or more (WAAVP).

28. Studies done more than 5 years ago

29. Two ways to test for anthelmintic resistance
Fecal egg count reduction test (FECRT)
 Compare before and after fecal egg
counts or after treatment egg counts.
 Need to test each drug separately
with individual or pooled samples
from 10-15 animals (same animals
each time)
 Cost of testing is variable.
$5-$20 per sample
Use pooled samples to reduce cost
 Producer can learn to do their own
fecals.
DrenchRite® Test
Larval development assay
 Determine dewormer resistance for
all dewormers simultaneously from a
single pooled fecal sample.
 Larvae ID is part of test.
 Dr. Ray Kaplan’s lab at University of
Georgia College of Veterinary
Medicine is only place that does test
in North America.
[ jscb@uga.edu]
 $450 per sample

30. FECRT: Old Guidelines (WAAVP)
 Utilize animals that have not been dewormed for prior 8-
12 weeks.
 Allocate animals to either a treatment or control
(nontreated) group. You’ll need a treatment group for
each dewormer you want to test.
 15 animals per group is recommended. The fewer
animals you have the less confidence you will have in the
results (from a statistical standpoint).
 Average FEC of group should be at least 250 epg.
 Lambs and kids are preferred age group to test because
they tend to have higher FECs.
 Compare FEC means of treated group to control group
10-14 days after treatment.
 >95% is indicative of drug susceptibility.

31. FECRT: New Guidelines (WAAVP)
 Compare pre- and post-treatment fecal egg counts
of treated animals; no control group is needed.
 15 animals per group. You’ll need a different group for
each drug you want to test.
 No minimum FEC is required, but eggs counted pre-
treatment across all animals should exceed 140,
though anything above 100 eggs should yield good
results.
 Use same number of slides/chambers for post-
treatment counting.
 Three highest egg counts shouldn’t account for more
than 50% of sum of all individual egg counts.
 Modified McMaster may not be appropriate if egg
counts are low.

32. FECRT: Pooled Fecal Samples
 Few sheep and goat producers test
for anthelmintic resistance.
 The use of pooled composite fecal
samples could reduce the cost of
testing and encourage more
producers to test for resistance.
 Research shows that there is little
difference in FECR results between
individual and pooled composite
fecal samples.

33. FECRT: Pooled fecal samples
 Collect paired fecal samples via the
rectum from a minimum of 15 animals.
 The same animals must be sample pre-
and post-treatment.
 Mix samples thoroughly.
 Weigh 1 g from each sample
 Combine into one composite sample.
 Follow new guidelines (WAAVP) for
determining FECR.
 Can also use multiple pooled composite
samples to determine anthelmintic
resistance.

34. Limitation of FECRT
 FECRT requires significant time and effort (cost).
 FECRT requires a lot of animals; most producers don’t
have enough.
 The fewer the animals tested, the higher the variability
will be; the less confidence in the results.
 The lower the pre-treatment FEC, the higher the
variability will be; the less confidence in the results.
 FECRT is only performed for a single dose (e.g. labeled
sheep dose or 2x label for goats).
 Observed efficacy is subject to high variability once it
falls below 95%.
 FECRT should only be used to indicate whether
resistance is present (or not).

35. DrenchRite® Test
Larval development assay (LDA)
 Determines resistance status to all drug
classes simultaneously from a single
pooled fecal sample.
 Eggs isolated from sample are placed in
specially-made well assay plates,
containing doubling concentrations of
the drugs.
 Critical well values which correlate to
fecal egg count reductions are used to
determine resistance.
 Resistance is present if the percentage reduction in fecal egg count is less than
95%.
 Depending upon level of resistance, actual efficacy may vary from 0 to 95%.

36. Determining anthelmintic resistance on
sheep farms in the Southeastern US
 Determine anthelmintic (dewormer)
resistance on 30 commercial sheep
farms (preferably 100+ ewes) in
Maryland, Virginia, and Georgia.
 Project funded by ASI’s Let’s Grow
Program.
1. University of Maryland
2. Virginia State University
3. Fort Valley State University
 Cost-share DrenchRite® test (larval
development assay; $450) to determine
anthelmintic resistance.
 Tests conducted by University of Georgia
College of Veterinary Medicine (Dr. Ray
Kaplan’s lab).
In 2016

37. DrenchRite ® Test results

38. Percent farms (n=26) with anthelmintic resistance
FECR <95%
0
10
20
30
40
50
60
70
80
90
100
Benzimidazoles Ivermectin Levamisole Moxidectin
Maryland Virginia Georgia
In 2016

39. Benzimidazoles (SafeGuard®)
Albendazole (Valbazen®), Oxyfendazole (Synanthic®)

40. Ivermectin (Ivomec®)
Avermectins: Doramectin (Dectomax®), Eprinomectin (Eprinex®)

41. Moxidectin (Cydectin®)

42. Levamisole®
Prohibit®, Leva-Med®

43. Anthelmintic (dewormer) resistance
 We can’t prevent the development of resistant
worms, but we can affect the rate by which the
worms develop resistance.
 On most farms, resistance is probably still at a
level where there is still time to slow it down
and enable the continued use of some
anthelmintics.
 Resistance was previously thought to be
permanent, but there is evidence of reversion
to susceptibility when combination treatments
(multiple drug actives) are combined with
resistance management strategies.

44.  Some level of “infection” is normal and
acceptable.
 The goal of an internal parasite control
program is to maintain welfare and
prevent clinical disease (production
loss), while preserving long-term
efficacy of drugs.
 Anthelmintics are a valuable, but limited
resource; regular deworming is no
longer advocated.
Control of internal parasites

45. Targeted Selective Treatment (TST)
 Only treating those animals which require
deworming or would benefit from treatment.
 Never treating the whole group.
 Increases refugia
Slows drug resistance
 Helps to identify resistant and susceptible
animals for selection and culling.
Refugia are worms (in animal
and on pasture) that have not
been exposed to drug, thus
remain susceptible.

46. Targeted Selective Treatment (TST)
Three on-farm decision making tools
1. FAMACHA© eye anemia system
2. Five Point Check©
3. Happy Factor™
Performance-based criteria

47. FAMACHA© system
 FAMACHA© system was developed for
small-scale sheep farmers in South Africa in
response to growing anthelmintic resistance.
 System validated for goats
 System validated in US for sheep and goats
 A system to assess anemia (primary
symptom of barber pole worm infection) in
sheep and goats and to determine the need
for deworming individual animals.
 Named for its originator:
Dr. Francois “Faffa” Malan
Faffa Malan Chart

48. 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
FAMACHA© system

49.  Addresses limitations of FAMACHA©, which is
only effective for blood feeding parasites, such
as Haemonchus.
 Extension of TST to determine need for
deworming for additional internal parasites that
affect sheep and goats.
 Especially useful when deciding whether or not
to deworm FAMACHA© score 3’s.
 Involves 5 check points on the animal: eye,
back, tail, jaw, and nose.
 Developed for sheep
 For goats, can replace nose
checkpoint with coat condition.
Five Point Check© 5.©

50. Check Point Observation Possibilities
1. EYE
Anemia
1-5
(FAMACHA© card)
Barber pole worm (Haemonchus)
Liver fluke
Hook worms
Other worms and causes
2. BACK
Body condition score
1-5
(BCS card)
Brown stomach worm (Teladorsagia)
Bankrupt worm (Trichostrongylus)
Nodular worm
Other worms and causes
3. TAIL
Fecal soiling
(1-5)
Dag score card
Brown stomach worm (Teladorsagia)
Bankrupt worm (Trichostrongylus)
Coccidia (Eimeria)
Nodular worm (Oesophagostomum)
Other worms and causes
4. JAW
Soft swelling
“Bottle jaw”
1-5
Barber pole worm (Haemonchus)
Coccidia (Eimeria)
Liver fluke
Hook worms
Other worms and causes
5. NOSE Discharge
1-5
Nasal botfly
Lungworms
Pneumonia
Other causes
5. COAT Coat condition
1-3
Barber pole worm (Haemonchus)
Brown stomach worm (Teladorsagia)
Bankrupt worm (Trichostrongylus)
Coccidia (Eimeria)
External parasites
Other causes

51. The Happy Factor™
“A happy sheep is a healthy sheep.”
 Developed in Europe and New Zealand,
where barber pole worm is not the
primary parasite, but “scour” worms are.
 Performance-based model; deworm
when animals fail to meet performance
targets.
 Live weight gain
 Milk production
 Will be most practical with use of
individual electronic ID and automatic
weighing platforms.
 More information/research needed. Not tested for barber pole worm: will it work?

52. Limitations of fecal egg counts as a
diagnostic tool
 Not a highly accurate test, especially at low numbers.
 Parasites vary in their egg producing capacity.
 Immature worms (L4s) suck blood, but do not lay eggs.
 Inhibited larvae do not lay eggs.
 There is a day-to-day variability in counts, even in stable
worm populations.
 Eggs are not always evenly distributed in manure.
 Loose stools (diarrhea) may underestimate egg counts.
 Some eggs look the same and cannot be differentiated at
the egg stage (e.g. Haemonchus vs. Trichostrongylus)
 Not all parasites (or strains) are pathogenic.
 There are different procedures for doing fecal egg counts.
 The possibility of human error.
 Should not be used as SOLE indicator of when/if to deworm animal.

53. http://www.wormx.info/combinations

54. Impact of using dewormers in
combination on efficacy of treatment

55. Efficacy of combination treatment
Efficacy FECR # eggs
1000
LEV 95% 950 50
MOX 95% 47.5 3.5
BZ 20% 0.7 2.8
998.2
99.8%

56. Using combination dewormers
 No combination dewormers are
available in the US.
 So -- each dewormer must be
purchased separately.
 And -- each dewormer must be
administered separately in a
different syringe.
 Each dewormer should be given
at full dose in a close time span.
 The withdrawal period for the dewormer with the longest withdrawal period
should be followed (is Cydectin® for sheep and goats).
 Use a Targeted Selective Treatment Approach: if you don’t maintain refugia,
eventually all dewormers will be ineffective.

57. Dewormers should not be mixed.
 They are not chemically compatible.
 Water soluble vs. suspensions
 Water soluble vs. lipophilic
 You don’t know how much to mix (how
many animals will require treatment)
 The purpose of combination treatment
is to increase the efficacy of a single
treatment. Why do something that will
jeopardize efficacy?
 FDA regulates compounding of animal
drugs. Only veterinarians are allowed to
compound medications.

58. Recommended combination treatment for
sheep and goats
Valbazen® Cydectin® Prohibit®*
Sheep 1.5 ml/50 lbs.
[7 days]
4.5 ml/50 lbs.
[7 days]
3.7 ml/50 lbs.
[3 days]
Goats 4 ml/50 lbs.
[9 days meat]
[7 days milk]
9 ml/50 lbs.
[17 days meat]
[8 days milk]
5.5 ml/50 lbs.
[4 days meat]
[3 days milk]
*Dose of Prohibit®
depends upon how
product is mixed. Dose is
given for dissolving 52 g
packet in 943 ml (1
quart) of water.
http://www.wormx.info/dewormers

59. Combination treatments
The time is now!
 The time for combination treatments is
not after resistance has become a big
problem.
 The earlier, the better.
 If you use combinations when the drugs
are still highly effective … there will be a
dramatic change in the evolution of drug
resistance in the worm populations on
your farm.
 If efficacy of dewormers >80%, you may
not notice any difference in clinical
response.

60. Using copper oxide wire particles (COWPs) to
increase dewormer efficacy
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%
Similar results would be
expected if COWPs were
combined with other
dewormers (e.g. Prohibit®).
USDA ARS (Booneville, AR) Study, Published 2016.

61. What are copper oxide wire particles?
 Small needles composed of copper oxide
(Cu20).
 COWPs have been shown to reduce barber
pole worm infections in sheep and goats;
exact mechanism of control is unknown.
 There are copper boluses (Copasure®, 12.5
and 25 g) available for cattle (for copper
supplementation) that can be repackaged
into smaller doses for sheep and goats.
 Buy gel caps and weigh out 0.5-1 g of
COWP needles (easy to do).
 Administer with balling gun, pet pilling gun,
or PVC pipe and dowel.
 Several companies sell COWPs in 2 and 4 g
dosages for goats (for copper
supplementation)
1. UltraCruz™
2. Copasure® (Animax)

62. Using COPWs for internal parasite control
in small ruminants
 COWPs should only be used as part of
a targeted selective deworming
program utilizing the FAMACHA©
system, Five Point Check©, or Happy
Factor™ (performance-based
deworming protocol).
 Know your copper status before giving
any supplemental form of copper to
livestock, especially sheep.
 The 2 and 4 g boluses of COWP should
probably not be used for deworming
purposes, especially for sheep. Lesser
dosages are effective and safer.

63. Field trial with COWP
2014 Western Maryland Pasture-Based Meat Goat Performance Test
 Mid-way through the test (d-42) which was at
the end of the “parasite challenge phase” of
test, test bucks (n=77) were given a gel cap
containing ~0.5 g of copper oxide wire
particles (COWPs).
 Nine bucks required deworming (based on
FAMACHA© scores and 5 Point ©) were
dewormed with a commercial dewormer
(either levamisole or moxidectin).
 Fifteen (15) bucks from the pasture group of
the pen vs. pasture study served as controls:
they did not receive any treatments. Pen group
also did not receive any treatment.

64. Field trial with COWPs
2014 Western Maryland Pasture-Based Meat Goat Performance Test
Treatment
#
goats
July 17
Avg. FEC
July 31
Avg. FEC
Avg.
FECR
Dewormer
Effective 8 8735 103 98.6
Ineffective 1 500 275 45.0
COWPs
Effective 53 2768 388 81.7
Ineffective 8 723 2000 < 0
No treatment
(Control)
Pasture 15 2164 2371 < 0
Pen 12 1216 758 37.7

65. Field trial with COWPs
2014 Western Maryland Pasture-Based Meat Goat Performance Testc
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
Test - COWP Study - no COWP
AVG
FEC
EPG
COWP

66. Field trial with COWPs
2014 Western Maryland Pasture-Based Meat Goat Performance Test
 Treatment with COWPs reduced FECs
by 74.6 + .09% (53-86 % CI),
compared to 92.9 + .09% (84-96% CI)
for the commercial dewormer(s).
 There was no reduction in fecal egg
counts in the CON group.
 COWPs were determined to be
moderately effective at reducing FECs,
but the effect was less than for the
commercial dewormer and by d-28,
FECs had increased to pre-treatment
levels.

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