EPM Equine Protozoa Myeloencephalitis

Any horse that eats hay, grain, or grazes in a pasture is susceptible to getting EPM. Equine protozoa myeloencephalitis (EPM) is an infection of the brain and spinal cord of horses by single-celled parasites known as protozoa which is carried by opossums.  Opossum feces can contaminate hay and grain out in the field or hay bales stored in sheds. The protozaon responsible for EPM gets mixed with the hay or grain and is then ingested by the horse.