December 2002

EPM Is Becoming A Catch-All Diagnosis

But it shouldn’t be. If the horse doesn’t have clear neurological symptoms, save your money. It’s not EPM.

Horses can pick up the EPM protozoa ûby grazing in infected areas.

We’ve come a long way since 1964, when Dr. James Rooney first described finding a protozoal organism in the brain of a horse with neurological disease—what we now know as EPM—but we still have a long way to go in preventing it and effectively treating it.

EPM, or equine protozoal encehalomyelitis, is a protozoal infection of the central nervous system. Most cases are caused by the organism Sarcocystis neurona, which the horse picks up from feed, the ground or possibly water contaminated by opossum feces that contain the infective cysts. …