Barber’s pole worms are a major problem for keepers of sheep and goats throughout the world. Bloodsucking gut-dwellers, barber’s pole worms (Haemonchus contortus) cause serious anemia and death if not aggressively treated. Females are prolific egg-layers, laying as many as 10,000 eggs per day, so large worm loads develop rapidly. Unfortunately, because of the overuse of dewormers that control this worm, resistance is a major problem.
The FAMACHA system (it stands for FAffa MAlan CHArt) was developed by three scientists in South Africa and introduced to North America by the American Consortium for Small Ruminant Parasite Control (ACSRPC). It helps producers single out individuals for treatment by matching the color of an animal’s eye mucous membranes to a chart showing five color categories indicating level of anemia. The colors go from category 1 (cherry red; not anemic) to category 5 (white; severely anemic).
Deworming only those animals that require treatment greatly decreases the development of resistance, because eggs produced by the few resistant worms that survive treatment will be greatly outnumbered by eggs shed by animals that weren’t dewormed. When all the animals in a flock or herd are dewormed and moved to clean pastures, only resistant worms that survive treatment will produce eggs to produce the next generation of worms.
Producers who wish to use FAMACHA should ideally seek training in its use. Contact your veterinarian, your cooperative extension agent, or the ACSRPC for information about workshops near you. The video below from the University of Rhode Island is another way to learn the basics.
FAMACHA scoring is as easy as Cover, Push, Pull and Pop.
• Cover the eye by rolling the upper eyelid down over the eyeball.
• Push down on the eyeball. The eyelashes of the upper eyelid tend to curl up over your thumb.
• Pull down the lower eyelid.
• The mucous membranes pop into view. Don’t score the inner surface of the lower eyelid, score the bed of mucous membranes.
Evaluate the pinkest part of the mucous membranes. Be quick; the longer membranes are exposed, the redder they get. Score both eyes; they might be different. And always check eyes in direct, natural light.
Check eyes every two weeks during the grazing season; during warm, wet weather, weekly is better. Barber pole worms are less active in spring and fall, so every three to four weeks is usually sufficient, and you need check only periodically during winter months. However, ewes and does experience a worm bloom when dormant internal parasites resume development after lambing and kidding, so they should be checked more often, even in the winter.
Deworm animals that score a 4 or 5. Don’t deworm those that score a 1 or 2. Lambs and kids, pregnant or lactating ewes and does, and thin or sick animals that score a 3 should be dewormed; healthy adults usually won’t need it. Once an effective dewormer is used, pale membranes should improve in a week or so.
Keep in mind FAMACHA scoring works only for barber’s pole worms. If infestation by other species is a concern, fecal sampling works best.