Prevalent Parasites: Common Types of Equine Internal Parasites

moves to the small intestine of the horse where it releases the tapeworms. Adult tapeworms then continue to move through the small intestine until they arrive at the ileocecal junction. This is the junction between the ilium the last part of the small intestine and the cecum. Here the tapeworms attach to the gut wall and may cause inflammation of the intestinal tract. Colic has been reported to be caused by tapeworms. Additionally obstruction ulceration or thickening of the intestines can occur because of heavy tapeworm loads.
Pinworms
Pinworms Oxyruris equi are ingested by the horse as eggs and can be found in the horses environment. Once ingested pinworms mature in the horses intestines. Adults then emerge out of the anus and lay eggs along the horses skin there which makes the horse itch and rub its tail. Unlike other parasites mentioned pinworms do not cause much harm to the horse internally but instead cause unattractive hair loss from the horse scratching its tail. They are not a large concern from a health perspective but treatment for this species of parasite is still recommended to reduce irritation.
Bots
Bots often referred to as stomach bots are unique because they are both internal and external parasites. The most common species of bot fly found in horses is Gasterophilius intestinalis. The adult bot fly an external parasite is a flying insect resembling a bee that lays yellowoval shaped eggs on the horses coat. Eggs are found primarily on the lower forelimbs and to a lesser extent the neck and mane. The eggs will remain there until stimulated to hatch by the horses saliva as it bites or licks the affected area. The newly hatched larvae burrow into the gums of the horse where they will stay for about four weeks. The parasites then move to the

lining of the stomach where they stay for nine months before being passed in manure. Possible minor oral lesions and damage to the stomach lining can occur from stomach bots but no serious health problems are generally caused by bots.
Threadworms
Threadworms Strongyloides westeri are internal parasites that primarily infect foals. Though they can be seen in older horses they are rarely found in horses over 810 months due to developed immunity. Foals become infected in three different ways by ingesting larvae through the mares milk from the larvae penetrating the foals skin or ingestion of the larvae from the environment. Larvae