How Do Horses Get EPM?

Find out the most common way horses contract equine protozoal myeloencephalitis, or EPM.
Share
Favorite
Close

No account yet? Register

ADVERTISEMENT

How Do Horses Get EPM?
The main protozoan that causes EPM, Sarcocystis neurona, is found in the scat of some opossums. | Photo: Thinkstock
Q: How do horses get equine protozoal myeloencephalitis (EPM), and what is the best way to prevent it?

—Emilee

A: The main protozoan that causes EPM, Sarcocystis neurona, is found in the scat of some opossums. The horse eats feed (hay or grain/concentrates) that is contaminated with S. neurona from opossum feces, and the protozoa gains entrance into the horse’s blood through the intestinal tract. (The protozoan Neospora hughesi also causes EPM, but the definitive host is not known).

In most horses S. neurona is killed by the horse’s immune system in the lymph nodes of the intestines. However, in some horses, the EPM protozoa is captured by white blood cells and passed across the blood-brain barrier into the central nervous system, where it infects the nerve cells

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:

Frank M. Andrews, DVM, MS, Dipl. ACVIM, is LVMA Equine Committee professor and director of the Equine Health Studies Program at Louisiana State University’s School of Veterinary Medicine. As an internal medicine specialist, Andrews research interests include equine gastric ulcer disease.

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?
277 votes · 277 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!