The ABCs of FECTs

The ABCs of FECTs

Fecal egg count tests allow veterinarians to develop a tailored deworming schedule for each horse.

Photo: Michelle N. Anderson, Digital Managing Editor

Dealing with poop is often one of the least favorite chores for horse owners, but manure can actually be a window into parasite surveillance and detection of dewormer resistance.

As more veterinarians recommend strategic deworming programs rather than rotational methods, fecal egg count tests (FECT) become especially important.

“Fecal egg count tests allow veterinarians to determine a tailored deworming schedule for each horse and to detect resistance on farms,” said Hoyt Cheramie, DVM, MS, Dipl. ACVS, manager of Merial’s Large Animal Veterinary Services. “Horse owners should work with their veterinarians to ensure that fecal egg count tests are properly conducted by independent, reputable laboratories.”

An FECT measures the number of strongyle eggs a horse passes in each gram of his manure. When you send a sample to your veterinarian, the results will consist of a number followed by EPG (eggs per gram), which will tell you whether your horse is a high (generally more than 500 EPG), medium (200-500 EPG), or low (less than 200 EPG) shedder. When performed properly, the results from FECTs can help determine the appropriate treatment protocol for your horse.

After the first FECT, your veterinarian might ask that you deworm your horse and take a second FECT two weeks later; this is known as a fecal egg count reduction test. If the egg count number has not dropped significantly from the first test, it indicates that the worms on your farm could be resistant to that dewormer’s active ingredient. In these cases, work with your veterinarian to determine the best course of action.

Remember that FECTs can easily be misinterpreted if samples are collected, handled, or analyzed improperly. A few guidelines from the American Association of Equine Practitioners:

  • Keep samples in containers or plastic bags that are airtight and won’t leak. Anaerobic conditions (those without oxygen present) will prevent eggs from hatching and developing;
  • Gather samples from your horse’s stall as soon as possible and refrigerate immediately. After 12 hours in the environment, the sample could be compromised;
  • Ensure the FECT is run within seven days of manure collection;
  • Do not freeze fecal samples; and
  • Do not use diarrhea for samples. The horse should have normal feces before an FECT is done.

It’s important to remember that fecal egg counts only test for strongyles and do not detect tapeworm eggs. Horses should be treated for tapeworms at least once a year, in the fall, to protect the animal and diminish transmission onto the pasture.

“Strategic deworming programs should be developed with veterinary guidance,” said Cheramie. “There is no one-size-fits-all program.”

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