Equine Protozoal Myeloencephalitis better known as EPM can be an awful problem to deal with. The disease is caused by the feces of opossums that contain sporocysts (cysts that contain spores that can reproduce asexually). Horses can ingest these sporocysts with feed, grass or water contaminated with opossum feces. The protozoa can leave lesions on the spinal cord and brain stem that attacks the horse’s central nervous system. It is this neurological damage that can cause symptoms of EPM.

Symptoms of EPM include:

Please note symptoms of EPM can vary between horses.

stumbling
head tilt
muscle atrophy
difficultly swallowing
sore back
loss of coordination
roaring
locking of the stifle joint
drooping eyelid
weakness

Call your veterinarian to get a closer examination by getting blood or spinal fluid tests to rule out diseases like West Nile Virus, rabies or viral encephalitis.
Younger horses and horses who are transported frequently seem to be at greater risk. Although, horses of any age can develop EPM. Risk is thought to be higher in the fall than at other times of the year. With quick professional diagnoses and proper medication most horses will recover from EPM, however some can experience permanent damage. Treatment includes anti-protozoal, anti-microbial and anti-inflammatory drugs administered by your veterinarian. Treatment may be lengthy and expensive.

To prevent this awful disease, you need to keep your barn area clean. Do not leave food out. Make sure all trash cans have a tight lid. To remove the opossums you can purchase human traps and relocate them.

Protazil, a pelleted product that can be added to your horse’s feed, is a new treatment option for EPM.