Llama Parasite Control

David E Anderson, D.V.M., MS, Diplomate ACVS
College of Veterinary Medicine
The Ohio State University, Columbus, Ohio

Llamas can acquire a great variety of internal and external parasites. Some of these are common to sheep, goats, cattle, and horses. Parasite control must be tailored to the individual farm - recommendations from other farms or other areas of the country have little usefulness on your farm. We recommend that parasite control strategies be developed through your veterinarian with the aid of fecal parasite egg counts. Further, we recommend that the Sugar Floatation Method be used for fecal egg counting because this method is more precise than traditional floatation methods. Fecal egg counts should be done at random and include all llamas if there are fewer than 10 animals on the farm, or 10 % of the herd if there are greater numbers of animals. Fecal egg counts done approximately 2 weeks after de-worming medication has been administered may aid in evaluation of development of parasite resistance.

Meningeal worm (Parelaphostrongylus tenuis) represents a significantly different problem to llamas. These worm larvae are passed through the feces of deer (natural reservoir), are consumed by snails, and then are consumed by llamas and alpacas. Llamas are not the normal host for these worms and they perform "aberrant migration". During this migration, they may travel into the spinal cord and cause significant harm to the host - even causing lethal consequences. Fencing deer out of the pasture is not enough and chemicals to kill snails cause environmental residues that may be harmful and are of limited efficacy. Therefore, most prevention against meningeal worm larval infection is aimed at killing the larvae during their migration, but prior to entry into the spinal cord. This requires a de-worming frequency of at least every 4 to 6 weeks at least during the high risk periods of the year (April-May through November-December in Ohio). The most efficacious anthelmintics for protection against meningeal worm have been ivermectin (1 cc of 1% ivermectin per 100 pounds body weight, injected under the skin, every 4 to 6 weeks) or fenbendazole (4.5 cc of 10 % fenbendazole per 100 pounds body weight, given orally, once daily for 3 to 5 days).