Last week we shared an article about the problem of parasite resistance to worming medications and covered worming practices that may help or hurt resistance. FAMACHA© scoring is one of the tools available to help prevent resistance in your herd. It’s a test for barberpole worms (Haemonchus contortus) in your herd, and uses the symptoms of anemia that the worm can cause to help us pick out the animals that need to be treated. By treating only the animals that need it instead of the whole herd, we make better use of our wormers, and reduce the potential for creating resistant worms.
FAMACHA© was created by a team that included Dr. Fafa Malan of South Africa (FAfa MAlan CHart). The chart they created as part of the process shows different possible colors of the membrane of the eye, from a dark red, or 1, indicating no significant anemia, to a white color, or a 5, indicating severe anemia. The light red, pink and pinkish white colors in between indicated by scores 2 through 4 indicate increasing levels of anemia that generally correspond to the parasite burden the animal is carrying.
This video from Dave Scott of ATTRA/NCAT shows how you “cover, push, pull and pop” the eye and it’s membrane so that you can get a good reading. (Simply pulling the bottom eyelid down won’t do, as the color you see will be paler and you’ll end up treating animals you shouldn’t.) He also demonstrates with his own 200 sheep how easy it can be to use on even larger flocks. He can FAMACHA© score 4 sheep in 30 seconds, and it generally takes only 2 hours to run his whole flock through the process.
Dave notes that, “The technique is not hard, but it needs to be done correctly in order to get accurate results.” If you’d like to learn how to “cover, push, pull and pop” and get your FAMACHA© card, click on over here to find a training in your area. If you don’t find what you need, check with your state’s sheep extension agents or see if your vet feels comfortable training you. Last but not least, there’s an online course from the University of Rhode Island here.
If you’ll be in Montana in July, sign up for the training that Dave Scott will be holding at his ranch in Whitehall on July 30. The short training includes an hour of classroom instruction on the life cycle of the barberpole worm, creating refugias to prevent wormer resistance, and how to graze to control parasites. Then you’ll head outside for an hour of hands on instruction with Dave’s sheep followed up by a potluck lamb dinner. The course is limited to 25 people so if you’re interested be sure to check in with Dave here.
Why do you not recommend culling the treated animals? Probably easier to develop resistant sheep than to avoid resistance in the parasites.
One issue with parasite treatment in general is that medications that treat parasites also tend to make the animal’s manure toxic to dung beetles. At least that’s my impression as a layperson