Treatment of Equine Gastrointestinal Parasites (16-Dec-2003)

Introduction Gastrointestinal parasitism remains a significant health problem in horses, although the nature of the problem has changed in the past 20 years. It is probably fair to state that ivermectin revolutionized control of gastrointestinal parasites of horses, but the use of ivermectin, or any other anthelmintic, did not eliminate equine gastrointestinal parasites. When administered at recommended intervals, the use of ivermectin did eliminate the devastating clinical disorders associated with Strongylus vulgaris (thrombo-embolism, verminous arteritis). Subsequently, clinical problems attributable to other endoparasites (small strongyles, tapeworms, roundworms) have become more notable. Reliance on anthelmintics to control endoparasites has led to the emergence of resistance to many anthelmintics, especially among the small strongyles, and this will require a more targeted approach to the management of parasites, under the supervision of a veterinarian.