Fecal Egg Count Tests Inprove Deworming Programs

Worried about resistance? Concerned that your parasite control program isn’t working as well as it used to? With questions like these, it can pay to incorporate fecal egg count reduction tests (FECRT) into your deworming program this fall.

“While FECRTs aren’t a definitive test for resistance, it’s a good start for evaluating what parasite loads your horses are carrying and what deworming products you should be using,” says Hoyt Cheramie, DVM, MS, manager, Equine Veterinary Services for Merial. “Without basic knowledge about the parasites present, horse owners may be deworming in the dark — and perhaps wasting money on products that aren’t appropriate.”

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A quantitative fecal egg count test examines the number of eggs in a small sample of manure to help indicate parasite levels within an individual horse or group of horses. When performed both before and after parasite control products are used, it can help horse owners and their veterinarians evaluate the product.

“For the best information possible, getting your veterinarian involved should be the first step,” Dr. Cheramie says. “FECRTs can be easily misinterpreted if samples are improperly collected, handled or analyzed. Work with your veterinarian to ensure FECRT analysis and additional tests are properly conducted by a veterinary clinic or by independent, reputable laboratories. Don’t rely on dewormer manufacturers’ labs to perform these diagnostics. Even in the cases where Merial needs to conduct an FECRT, we rely on independent, university-based parasitologists.”

Veterinarians will analyze the results to determine the type of parasites and any variability in egg output between horses or between fecal egg count tests if these tests have been performed previously. Veterinarians consider these factors, among others, like the age of the horse, when making deworming recommendations.

In addition, horse owners shouldn’t expect information on tapeworms as there is no reliable diagnostic test for active tapeworm infection.

“After reviewing the results, don’t be surprised if your veterinarian recommends a new deworming product or no product at all,” Dr. Cheramie says. “There is well-documented evidence that some entire classes of dewormers may not work against key parasite threats.”

“Even when using a dewormer that works, the goal of today’s equine parasite control program isn’t to eliminate all worms. The important considerations are reducing parasite transmission, keeping worm burdens below harmful levels and treating clinically affected horses. While not perfect, FECRTs are the best start to shedding some light onto the performance of your current equine deworming program.”