Equine Protozoal Myeloencephalitis: Past and Present

EPM still frustrates horse owners and veterinarians as one of the most common neurologic diseases in horses.
Share
Favorite
Close

No account yet? Register

ADVERTISEMENT

Equine protozoal myeloencephalitis (EPM) continues to frustrate North American horse owners and veterinarians as one of the most common neurologic diseases in horses–and one of the most challenging to diagnose and treat. At the 2011 Western Veterinary Conference, held Feb. 20-24 in Las Vegas, Nev., Steve Reed, DVM, Dipl. ACVIM, of Rood & Riddle Equine Hospital in Lexington, Ky., delivered an overview of the disorder and discussed diagnostic and treatment options.

Background

Reed explained that EPM was first noted in Kentucky and Pennsylvania in the 1970s, and the causative organism (a protozoon called Sarcocystis neurona) was first identified in the 1980s. Later, researchers determined that S. neurona has a two-host life cycle. To complete its life cycle, this organism requires a definitive host (the opossum), which feeds on the muscles of a dead intermediate host (such as a raccoon, skunk, cat, or armadillo) containing S. neurona sarcocysts. Once ingested by the opossum these sarcocysts mature to their infective stage (sporocysts), which the opossum passes in its feces.

Horses, which are generally considered "dead-end hosts" (meaning they typically can’t pass the protozoa on to other animals), contract the disease by ingesting infected matter, often grass or hay contaminated with opossum feces containing S. neurona sporocysts

Create a free account with TheHorse.com to view this content.

TheHorse.com is home to thousands of free articles about horse health care. In order to access some of our exclusive free content, you must be signed into TheHorse.com.

Start your free account today!

Already have an account?
and continue reading.

Share

Written by:

Erica Larson, former news editor for The Horse, holds a degree in journalism with an external specialty in equine science from Michigan State University in East Lansing. A Massachusetts native, she grew up in the saddle and has dabbled in a variety of disciplines including foxhunting, saddle seat, and mounted games. Currently, Erica competes in eventing with her OTTB, Dorado.

Related Articles

Stay on top of the most recent Horse Health news with

FREE weekly newsletters from TheHorse.com

Sponsored Content

Weekly Poll

sponsored by:

Where do you primarily feed your horse?
299 votes · 299 answers

Readers’ Most Popular

Sign In

Don’t have an account? Register for a FREE account here.

Need to update your account?

You need to be logged in to fill out this form

Create a free account with TheHorse.com!