Most Effective Pinworm Treatment for Horses

Pinworms are parasites found in the horse's rectum that are thin and about an inch and three-quarters long. Most of the dewormers available on the market for horses are effective against pinworms, but the class of dewormer most effective depends on the area in which your horse lives. Though rotational deworming used to be considered the best method for deworming your horse, parasites have developed resistance to certain products and your current deworming product may be entirely ineffective.

  1. Fecal Egg Count

    • Perform a fecal egg count on your horse using your current dewormer to determine if the pinworms in your area have developed resistance to certain products. Fecal egg counts are done by gathering a few balls of manure and placing them in a container such as a glass jar. Between 10 and 14 days after deworming your horse, you'll collect a manure sample again. Both samples should be sent to an independent laboratory or your veterinarian for examination. If the samples show a decrease of 90 to 100 percent between the first and second samples, your current deworming product is effective and you can continue using it. If not, experiment with another product with a different active ingredient. Active ingredients in dewormers that can be used against pinworms are ivermectin, moxidectin, oxibendazole, pyrantel pamoate, pyrantel tartrate and fenbendazole.

    Prevention

    • Books on grooming may instruct readers to use sponges to wipe down the area under the horse's tail, but pinworms can be spread to other horses by this method if the sponge is used on other horses. Instead, use paper towels or disposable wipes so that you can clean your horse without infecting other horses.