PowerPoint presentation for FAMACHA workshops by Jim Miller, retired Louisiana State University

1. Integrating Anthelmintics, FAMACHA
and Other Alternative Measures for
Controlling Nematodes in Small
Ruminants
American Consortium for Small
Ruminant Parasite Control

2. Overview
• Biology of Haemonchus contortus
• Understanding drug resistance
• Diagnosis of drug resistance
• Concept of “Smart Drenching”
• FAMACHA – concepts and practice
• Non-chemical approaches

3. Background To The Problem
• Abomasal and intestinal
worms are the most
important (??) pathogens
of sheep and goats
• Worm control has relied
almost exclusively on the
frequent use of
anthelmintics
– Resistance is now
common
• American Consortium for
Small Ruminant
• Parasite Control
Group Formed in 2001

4. Gastrointestinal Nematodes (Worms)
of Small Ruminants
• Abomasum
• Haemonchus contortus* (southeast US) – Barberpole
worm
• Teladorsagia circumcincta – Brown stomach worm
• Trichostrongylus axei
• Small intestine
• Trichostrongylus colubriformis – Bankrupt worm
• Cooperia
• Nematodirus
• Coccidia (protozoa, not worm)
• Large intestine
• Oesophagostomum – Nodular worm
• Trichuris - Whipworm

5. Haemonchus contortus
(Barberpole Worm)
• Sheep, goats, deer, exotic ruminants
• Blood-sucking worm
• Highly pathogenic
• Anemia
• Hypoproteinemia -- “bottle jaw”
• Most important worm parasite in
sheep/goats raised in warm/wet
environments
• Southeastern US, but becoming
more of an issue in northern cooler
areas with warm wet summers

6. Life Cycle of H.
contortus
http://www.ext.vt.edu
/pubs/sheep/410-
027/figure1.html

9. Why is H. contortus such a problem?
• Evolved in tropics
• Thrives in warm/wet climates
• Very fecund ~ 5,000 eggs per day
• 30 goats/sheep
• 300 worms/animal
• 1.5 million eggs per day per animal
• Over 1 billion eggs per month
• Long transmission season - southeastern US
• Short life cycle – 4/5 weeks during summer
• Immunity to worms is slow to develop
• Can take up to 6-8 months of age
• Immunity wanes around the time of parturition

10. Background to the Problem
• Age of modern anthelmintics
• Parasitologists recommended strategies
that maximized benefits of deworming
• Ignored resistance issues
• Over-reliance on anthelmintics
• Over-use of anthelmintics
• Prophylactic vs. therapeutic
• Loss of common sense management-
based approaches

11. We Created Our Own Problems
• This strategy has turned out to be shortsighted and
unsustainable
• The prevalence of multi-drug resistant H. contortus is
extremely high
• We are at risk of having no effective anthelmintics to use
in the near future
• “We have what we have”
• > $200 million to develop new drug
• New ones coming (hopefully, when is ??)

12. Anthelmintic Resistance
• The ability of worms to survive dewormings that are generally
effective at the recommended dose rate
• Considered a major threat to the current and future control of
worm parasites of small ruminants and horses
• Becoming an issue in cattle
• Development of resistance
• Deworming eliminates worms whose genotype renders
them susceptible
• Worms that are resistant survive and pass on their
“resistant” genes
• Resistant worms accumulate and finally deworming is
ineffective
• Clinical definition = <95% reduction in fecal egg count

13. Parents
Selection for
Resistance
Resistant
Next Generation
Resistant
Deworming

14. Where Did We Go Wrong - What
Actually Causes Resistance?
• Deworming at frequent intervals
• Many farms > 6 dewormings per year
• Dewormiing all animals at same time
• No refugia
• Deworming and moving to clean pasture
• No dilution
• Under dosing
• Worms with low-level resistance survive

15. Refugia
• The proportion of the population that is not selected by
deworming
• “In Refuge” from drug effect
• Provides a pool of susceptible genes
• Dilutes resistant genes in that population
• Until recently, overlooked as the most important
component of anthelmintic resistance selection

16. Resistance is Inevitable
• Natural biological consequence of deworming
• What Can We Do ???
• Rate of selection for resistance can be
greatly reduced
• ‘Smart Drenching’
• FAMACHA
• Preserve dewormer efficacy for as long as
possible

17. Anthelmintics (Dewormers)
• Benzimidazoles
• Albendazole (Valbazen)
• Fenbendazole (Safegard, Panacur)
• Oxifendazole (Synanthic)
• Imidazothiazoles
• Levamisole (Prohibit, Tramisol, Levasol, Rumatel)
• Macrocyclic Lactones
• Ivermectin (Ivomec)
• Doramectin (Dectomax)
• Moxidectin (Cydectin)
• Eprinomectin (Eprinex, LongRange)
• Amino-acetonitrile derivatives (AAD) – Canada, Not in US
• Monepantel (Volvix)
• Spiroindoles – Canada, Not in US
• Derquantel with abamectin (Startect)

18. Prevalence of Resistance
(H. contortus)
• Common
• Benzimidazoles (Valbazen, Panacur,
Safeguard), Ivermectin (Ivomec) and
Doramectin (Dectomax)
• Lowest level of resistance
• Levamisole (Prohibit)
• Becoming widespread rapidly
• Moxidectin (Cydectin)

19. Is It Really as Bad as it Sounds?
• Resistance is relative
• Not all worms on farm are resistant
• Killing some worms may relieve disease
symptoms
• Clinically it appears that the deworming was
effective
• Animals require deworming again very soon
• Eventually most worms become resistant and
deworming fails – animals may die

20. Scatter Plot of Anthelmintic Efficacy on
18 Goat Farms

21. What Does All This Mean For The
Small Ruminant Industry?
• Anthelmintics can no longer be thought of as a
management tool to be used exclusively to
improve animal productivity
• Reality = effective long-term control of worms
(especially Haemonchus) will only be possible if
anthelmintics are used intelligently with prevention
of resistance (not disease per se) as a goal

22. When to Suspect Resistance
• When fecal egg count remains high or clinical
signs persist following deworming
• One must also rule out other possibilities with
similar clinical signs
• Other infectious disease
• Nutritional deficiency
• Knowledge of prevalence of resistance in the
local area

23. Causes of Dewormer Failure Other Than
Resistance
• An inadequate dose was administered
• Underestimated weight
• Spilled/spit-out
• Errors of calculation
• Suspensions not thoroughly mixed before use
• Invalid extrapolation of dose from other hosts
• Activity is reduced
• Beyond its expiration date
• Stored improperly
• Errors in methods used for fecal egg count
• An improper or non-quantitative egg counting technique was used
• Fecal egg count was rechecked too late after deworming to detect an effect
of a short acting dewormer (reinfection has occurred)
• Fecal egg count was rechecked too soon for long acting dewormer to have
worked

24. McMaster Fecal Egg Count
• Quick, easy to perform
• Should be part of routine
services offered
• Slides available from:
• Chalex Corp (vetslides.com)
• chalexLLC@gmail.com
– Quickest response
• P.O. Box 981956
• Park City, UT 84098 USA
• FAX: (503) 914-0379
• Green grid

25. Diagnosis of Resistance
• Producer/Veterinarian in the field -- simple on-farm
anthelmintic trial
• Fecal egg count reduction test
• Fecal egg count at deworming and again 7-
14 days later
• Laboratory – DrenchRite
• Dr. Ray Kaplan’s lab (UGA) - $$$
• Only one test needed per farm
• One pooled fecal sample from 10 animals
• All 3 major dewormer classes tested in assay

26. “Smart Drenching”
• An approach whereby we use the current state of
knowledge regarding:
• Host physiology
• Anthelmintic pharmacokinetics
• Parasite biology
• Dynamics of selection for resistance
• Resistance status of worms on the farm
• To develop strategies that maximize the
effectiveness of dewormings while also
decreasing the selection of resistance

27. Proper Dose/Drenching Technique
• Ensure proper dose is delivered
• Proper technique when drenching ruminants is very
important
• Critical that the full dose lodges in the rumen
• If drench is delivered to the buccal cavity, rather than
into the pharynx/esophagus
• Can stimulate closure of the esophageal groove
with much of the drench bypassing the rumen
• Faster drug absorption
• Shorter duration
• Efficacy is reduced

28. Host Physiology - Maximize Efficacy
• Restrict feed intake for 24 hours prior to
deworming
• Once in the rumen, the duration of the
dewormer effect is largely dependent on the
flow-rate of the digesta
• Decreasing digesta transit leads to an
increase in dewromer contact with worms
and increased efficacy

29. Proper Dewormer Dosage and
Administration
• Goats metabolize dewormers much more rapidly than other livestock
• Rule of thumb -- goats should be given a dose 1.5 to 2 times
higher than for sheep or cattle
• Levamisole 1.5 X
• All others 2X
• Administer all dewormers orally
• Pour-ons are absorbed poorly
• Injectibles have long residual - resistance
• Combinations
• Combination (2-4 anthelmintics) products currently used in
Australia/NZ are being pursued for FDA approval in US
• Administering 2 or more dewormers (different classes) is now being
promoted to slow development of resistance

30. Do Not Buy Resistant Worms
• All new additions should be quarantined and aggressively
dewormed upon arrival
• Deworm with at least 2 dewormers with different
mechanisms of action (different class)
• Valbazen and Prohibit, for example, upon arrival
• Should remain in quarantine for 10 - 14 days
• Perform fecal egg count to confirm that minimal eggs
are shed
• If quarantine is not possible:
• Deworm with at least 2 dewormers and confine to pens
for a minimum of 48 hours following deworming

31. Selective Deworming
FAMACHA

32. Concept Behind Selective
Deworming
• Worms are not equally distributed in groups
of animals
• 20-30 % of animals harbor most of worms
• responsible for most of egg output

33. 0
4000
8000
12000
16000
20000
FEC
0
1000
2000
3000
4000
Individual Goats
FEC
33% of Goats
80% of Eggs
Distribution of FEC/Infection
Deworm high 33%
Greatly Reduces Daily
Pasture Contamination
With Eggs
Over 1 Month: Pasture
Contamination
Reduced By: 5.7
Billion Eggs
230 M
33%
46 Million
66%

34. Impact of Selective Deworming
on Refugia
• The more of the population that is in refugia, the
slower the rate with which resistance develops
• Selective deworming significantly increases the
percent of the population in refugia

35. How to Achieve Selective Deworming
 ID Poor doing animals
 Fecal egg count (FEC)
 Includes all worms – can’t
distinguish
 The FAMACHA© system
 Technique for the assessment of
Haemonchus infection
Indirectly evaluate worm
burden by level of anemia
 Selective deworming leads to a
substantial reduction in dewormer
usage

36. 5-Point Check

37. The FAMACHA© System
• Named for its originator
• Dr Francois “Faffa” Malan
• FAffa MAlan CHArt
• Drs. Jan van Wyk, Gareth Bath, Adriano
Vatta, Tami Krecek and Jørgen Hansen

38. The FAMACHA© System
• Eye color chart with five color
categories
• Compare chart with color of
mucous membranes of sheep
or goat
• Classification into one of five
color categories:
• 1 – not anemic
• 5 -- severely anemic

39. • Examine in sunlight
• Open as shown - for a short time only
• Look at color inside lower eyelid

40. Always Use Card !!!
Compare eye color to chart

41. Other Recommendations for
Proper Use
• Check both eyes
• Score animal based on lowest eye score
• No ½ scores
• Assign lower whole number score if unsure
• Do not hold eye open more than few seconds
• Wait and retry in other eye
• Keep records !!!!
• Record numbers of animals in each category on the block
histogram sheet provided
• An easy visual record of situation in herd/flock

43. FAMACHA©
• Use as guide to determine which animals to
deworm
• Significantly reduces number of dewormings
given when compared with conventional
deworming practices
• Should significantly decrease the rate of
development of resistance
• Only useful where H. contortus is the primary worm
species

44. Integrating the FAMACHA© System
• Start examining at two week intervals in the spring
• Treat categories 4 and 5
• Go to one week intervals as necessary during Haemonchus
“season”
• In cooler times of year every 4 to 6 weeks may be sufficient
• If >10% of flock/herd in categories 4 and 5, start deworming 3s
as well
• Change pastures if possible
• Do not deworm all animals before move
• Examine especially animals which lag behind the flock/herd
• Check for animals with “bottle jaw” and deworm these,
regardless of whether they look anemic or not

45. Precautions
• Paleness or reddening of the eyes may have other
causes
• Other causes of anemia:
• Other parasites
• Nutritional deficiencies
• Other diseases
• Other causes of redness:
• Environmental conditions
• Other diseases
• Infectious eye diseases

46. Precautions
• Only properly trained persons should apply the
FAMACHA© system
• The card is an AID in the control of Haemonchus only
• Replace card after 12 months’ use
• Maintain management-based worm control measures
• The system is best used by producers where back-up
assistance is available from a veterinarian

47. Other Advantage of Selective
Deworming (FAMACHA)
• Identify animals that need deworming most often
• These are the ones contaminating the pasture for
others in the herd/flock
• Cull these and improve genetics of resistance of
the herd/flock
• You now have a measure for determining start and
severity of worm transmission
• Will change from year to year depending upon
weather

48. Where Do I Get FAMACHA Cards?
• By request of Professor Bath in South Africa,
only properly trained lay individuals can
purchase the cards
• Sanctioned Training Workshop
• Online training (wormx.info)
• Through a veterinarian
• Vets expected to train themselves before
training others
• Information at famacha@uga.edu

49. Alternative Methods for
Worm Control

50. Breeding for Resistance
• Select resistant individuals (FEC/FAMACHA) and cull
susceptible animals
– Estimated Breeding Values
• National Sheep Improvement Program
• Katahdin, Polypay, etc.
• Goats can participate
• Use resistant breeds for crossbreeding (Commercial)
• Long term process, but will be rewarding

51. Copper-oxide Wire Particles
• Haemonchus only
• Marketed for use in cattle/small ruminants
(Copasure/UltraCruz) for copper deficiency but also
kills abomasal worms
• Appears to work better in sheep but potentially toxic
• Works synergistically with dewormers
• Selective deworming for individuals
• FEC/FAMACHA
• Copper sulfate added to feed or as a drench does
not work as well

52. Condensed Tannin Containing Plants
 Sericea lespedeza
 Forage that grows relatively well in SE US
Establishment as pasture may fit some operations
Hay, meal, pellets, etc. may be suited for other
operations
Sims Bros. (simsbrothers.com)
 Has effect on Haemonchus
– Female worms lay fewer eggs
• Reduced pasture contamination
– Kills some worms

53. Worm-trapping Fungi
• Duddingtonia flagrans
– Affects all worm larvae in feces
– Mix with supplement for daily administration or with loose
minerals for extended administration periods
– Primary objective is to clean up pasture
• Long term results (?, maybe 2-3 years)
– Available (BioWorma and Livamol/BioWorma) through Premier
One and veterinarians
• Cost is relatively high, but should come down as market
dictates

54. Vaccine
• Promising for Haemonchus
– Barbervax - works well in sheep, not so in goats
– Drawback is that vaccination has to be done
frequently (4-5 times each year) because protection is
not complete
– Originally expensive to produce
• Refined product has been developed
– Cost is now acceptable in Australia, but will not
be marketed in the US (??)
• Other vaccines for multiple worms have been
investigated, but protection is variable

55. Herbals/Diatomaceous Earth
• Many promoted as effective for controlling worms
• Scientific studies to evaluate some of these
indicated there is limited or no effect
– Maybe they make the animal feel and look better
in spite of being infected
• impression that worms are gone or fewer in
number
• Using these products should be done with caution,
especially in areas where heavy infections occur

56. Integrated Strategy
• Use FAMACHA/FEC for monitoring infection level
• Cull high infection individuals – resistance selection
• Deworm individuals as necessary
• Effective drug – smart drenching
• Copper oxide wire particles
• Sericea lespedeza
• Worm-trapping fungus
• Management
• Stocking rate, mixed species grazing, dry lot, pasture
spelling, etc.
• Future – New drugs, vaccine (??)

57. Seasonal Control Considerations
• Spring
– Immature and mature Haemonchus contortus
– Immature Fasciola hepatica (liver fluke)
• Summer
– Immature and mature Haemonchus
contortus*
– Immature and mature Fasciola hepatica*
– Flies*/Ticks
– Coccidia*

58. Seasonal Control Considerations
• Fall
– Mature Haemonchus contortus
– Mature Fasciola hepatica*
– Dictyocaulus filarial (lungworm)
– Lice/Mites
• Winter
– Mature Fasciola hepatica*
– Dictyocaulus filaria*
– Melophagus ovinus* (Sheep ked – wingless fly)
– Lice*/Mites*

59. Healthy Harmony

60. American Consortium for Small
Ruminant Parasite Control
(Wormx.info)

61. Questions?