Parasites are a common problem in small ruminants. Tufts Ambulatory Service can help you determine what types of parasites are infecting your animals and what is the best method to control those parasites.
Fecal egg reduction counts are commonly used to determine what types of parasites are infecting an animal and the efficacy of any dewormers used. A fecal sample is taken from an individual animal and tested for type and quantity of parasites. The animal is usually dewormed the same day that the fecal sample is taken. Another fecal sample is tested three to four weeks later, and if the dewormer is effective, the parasite egg count should be reduced by at least 95%. If not, the dewormer is ineffective and a different dewormer should be used.
Famacha scoring can be used to test for the parasite Haemonchus, which sucks blood and makes animals anaemic. This test involves looking at the mucus membranes of the eyes to see how pink they are on a scale of one to five, where five is pink and one is anaemic.
The DrenchRite Larval Development Assay, run by the University of Georgia, can be an especially useful test for people with large herds. A large fecal sample with high egg counts is taken from the farm, and those eggs are tested for sensitivity to a variety of dewormers, so that you can start by using the most effective dewormer available, rather than wasting time and money with trial and error.