Equine Protozoal Myeloencephalitis

Equine Protozoal Myeloencephalitis, or EPM for short, is a disease which affects a horse's nervous system, commonly displayed as paralysis or lameness. Horses exported from or located in North and South America, as well European regions such as the United Kingdom and France, have been detected with EPM. Moreover, younger horses and mares that are near foaling (or about to give birth) are more susceptible to this protozoal infection. EPM is very serious and requires immediate veterinary care.

Symptoms

Horses with EPM may display a variety of symptoms which can be disturbing to a horse owner; among them:

• Lameness
• Loss of muscle movement coordination (ataxia)
• Total paralysis
• Paralysis of the lips/ears
• Droopiness in the eyelids
• Difficulty eating (i.e., inability to chew or swallow food)

Cause

EPM is an infection due to the protozoal organism Sarcocystis neurona. It is believed it is transmitted through intermediate hosts such as birds or oppossum through their infected fecal matter. However, horses are not thought to be able to pass it along to another horse.

Diagnosis

Your veterinarian will typically rule out the numerous other neurological conditions that may cause paralysis in horses before conducting tests to locate the EPM-causing organism in the animal.