Tapeworm in a Horse

There are three different species of tapeworms, which affect the horse, Anoplocephela perfoliata, are the most common. It lives in the junction of the horse's small and large intestines--the caecum. It is a flat worm approximately 8-10 cm long and 1 cm wide. Tapeworms can affect all horses, regardless of age, breed and sex.

  1. Life Cycle

    • The adult tapeworm sheds segments of its body, which contain eggs and are passed out in feces. These segments son break down and release the eggs on to the pasture where small mites called orbital mites, which live in the base of the turf, consume them. Here they develop for four months until they find their way inside the horse when the mites are consumed with a mouthful of grass.

    Symptoms

    • Acute attacks of colic occur if large numbers of tapeworms damage and interfere with the efficient working of the ileocaecal valve. According to the University of Kentucky, Cooperative Extension Service, "There may be ulceration, inflammation, and formation of a diphtheritic membrane where the parasites are attached. " As the damage becomes chronic, unthriftiness, diarrhea and weight loss, with sporadic cases of colic are typical.

    Diagnosis

    • Occasionally, you can see worms in the horse's feces. However, not seeing the eggs in the feces does not mean the parasite is not present. A blood or serology test provides a conclusive diagnosis of tapeworms. Egg cases are capable of movement and look like pieces of rice.

    Treatment

    • In 2006 the FDA approved the use of praziquantel, combined in anthelminitc products with one of the avermectins as an effective treatment for tapeworms in horses.

    Prevention

    • Preventative treatment includes a twice-annual treatment with a double dose of Strongid-P. This removes a high percentage of tapeworms present in the caecum. Give the first dose 6 to 8 weeks after the horse is turned out in the spring, and the second in the fall.