No new anthelmintics with newer modes of action have been introduced since the early 1980s. Anthelmintic resistance continue to increase in cyathostomin and Parascaris spp. parasites. While resistance is slow to develop, work by Dr. Gene Lyons clearly illustrates that once it appears in a parasite, it is there to stay.
We can expect resistance to at least one drug class to be present in every equine operation across the world, and an overwhelming majority will feature multi-drug resistance. With only three classes to choose between, we are running out of treatment options.
Source: Equine Disease Quarterly, April 2017.
Perhaps the most important element in future parasite control programs is utilization of good diagnostic tools. Fecal egg counts will remain a cornerstone of control programs, but they have limitations in not providing information about larval stages and specific types (species) of parasites present.
INSIGHTS: Sales reps and retail associates can use this article to discuss parasite control with horse owners, dealers and veterinary teams.