A parasitic roundworm found in the intestines of equine hosts
Parascaris equorum is a parasitic nematode that infects horses and other equids. It is typically found in the host’s small intestine. The species belongs to the family of Ascarididae, Phylum Nematoda.
P. equorum shows sexual dimorphism. The female adults are larger than the male adults. The females can reach 38 cm in length. Both males and females are yellow-white in color. The eggs have a thick shell and are expelled in feces. Consumption of grass contaminated with P. equorum eggs may lead to the infection of the horse or equid. The eggs that are swallowed release the larvae. The larvae migrate into the small intestine where they will reach maturity. During the larval migratory phase, ascariasis in other body parts may occur. For instance, the larvae may migrate to the lungs and liver and cause inflammation.
No cross infection is reported between equids and humans or other animals.1
Word origin: Greek askarís (“an intestinal worm”)
- Kingdom: Animalia
- Phylum: Nematoda
- Class: Secernentea
- Order: Ascaridida
- Family: Ascarididae
- Genus: Parascaris
- Species: Parascaris equorum
1 Briggs, K. (March 1, 2004). “Ascarids: A Growing Problem”. The Horse. Retrieved from ://www.thehorse.com/articles/10920/ascarids-a-growing-problem.