Craig suggested treating all horses during the winter with ivermectin to combat bot fly larvae “A good reminder, is to treat your horse with ivermectin around Christmas time,” Craig said. “They often acquire bot larvae during the fall months, so winter is really the best time to deworm with ivermectin.
Aside from bot fly larvae, other, less common parasites are pinworms and tapeworms. Horses with pinworms are typically kept in stalls. One of the most common signs of pinworm infected horses is an itchy tail. Craig suggested treating an infected horse with a fenbendazole dewormer once a month, for three months along with a good shampoo of the horse’s rear end.
“The pinworm eggs can only survive about 30 days, so I recommend vacating the stall for a month until the eggs die on their own,” Craid added. “There is no product to kill the eggs, but allowing them to die on their own can be helpful in preventing re-infection”
Tapeworms can cause mild colic in horses because they often attach to the valve between the small and large intestine. Craig recommended deworming in the fall (September, October, or November) with a dewormer containing praziquantel or a double dose of pyrantel.
These recommendations are all suggested guidelines for parasite management in horses. Craig recommended following these guidelines, particularly in the Texas region. Altering deworming according to your horse’s age and parasite testing results are the two most important guidelines and can help horse owners develop an effective and sustainable parasite program, Craig said.
Pet Talk is a service of the College of Veterinary Medicine & Biomedical Sciences, Texas A&M University.