Tapeworms (Anoplocephala perfoliata)

Lifecycle: Tapeworm eggs develop in the oribatid "grass" mite, over 2-4 months. When infected mites are swallowed, tapeworms mature inside the horse in 4-6 weeks.

How It Gets Into Your Horse: The horse ingests infected mites.

Dangers If Left Untreated: Severe tapeworm infection can cause intestinal irritation. Fatal intestinal blockage can occur as worms accumulate at the ileocecal junction - the 3-way junction between the small intestine, large intestine, and cecum. New research shows that over 50% of horses tested in the US have been infected with tapeworms.