*Equine protozoal myeloencephalitis, EPM, is a neurological disease that effects the central nervous system of a horse. The intracellular protozoan parasite that attack the nervous system is known as – Sarcocystis neurona. Most often horses contract the EPM parasite from oppossom feces, which could come from contaminated food (hay or pasture).
There are no clear symptom that scream EPM, some horses affected could just seem “off” or “not quite right”. However a few symptoms that could point you in the direction of EPM are: asymmetric atrophy (muscle wasting) and ataxia (in-coordination). A horse could appear to have hind limb problems, e.g. stifles catching or mild lameness. Even something as simple as an extra droopy eyelid or lower lip.
A good start for you diagnosis in EPM is doing a neurological exam. Which involves various tests including:
- longeing
- walking up and down steep hills
- crossing front legs
- crossing hind legs
- walking with their head up in the air
- pulling their tail to the side while walking
Depending on the severity of neurological signs in these tests will determine where you will go from there. In my case we ran blood work, an EPM titer, we didn’t bother with the western blot because in our area almost every horse will show they have been exposed to the protozoa. However the western blot may be a viable option for you. Other EPM tests include the PCR testing, Immunofluorescent Antibody Test, ELISA, or Gene Expression Identification.
This will be a continuing series documenting my experience with EPM along will all the information I’ve gathered along the way.
