General Information On EPM In Horses

By Lila Barry


Equine protozoal myeloencephalitis, which may also be referred to as EPM, is a disease that affects horses. EPM in horses is the result of a protozoal infection within the central nervous system, CNS, of the animal. Jim Rooney, a doctor, was the first to discover this condition around the 1960s.

EPM is generally considered a rare condition. In more recent times, a high occurrence of cases has been reported. Research work was performed at the University of Kentucky. The results found that opossum is the definitive host for this specific disease.

The cause of EPM is two types of parasites: Sarcocystis neurona and Neospora hughesi. Much more information is known about the former than the latter. In fact, it is known that Sarcocystis neurona requires two hosts in order to fully complete a life cycle. One must be intermediate and the second must be definitive. In laboratories, sea otters, armadillos, skunks, raccoons and cats have all been known to act as intermediate hosts.

As stated, opossum is the definitive host for EPM. Usually horses get this disease from watering or grazing in locations near where possums have recently defecated. These animals are unable to pass the disease alone. That is, one horse that is infected cannot pass it on to another horse that is not. The horse is a dead-end host of the parasites.

There are certain symptoms caused by this condition. Some of the most common signs is asymmetric incoordination, spasticity and weakness. Although the symptoms may mimic nearly any neurologic disorder. Overall, symptoms may be classified as primary or secondary. Some signs are more difficult to categorize from other problems. Other symptoms to look for when identifying this problem: laryngeal hemiplegia, snoring, and muscle atrophy of some sort.

Not much is known about the way Sarcocystis neurona can enter the CNS of this animal. Nonetheless, it is thought to infect white bloods cells so it may cross into the brain. The disease is treatable. Some horses may have irreversible damage done to their system as a result of this particular disease.

It is crucial that the problem be identified early on so that treatment can be issued, in the form of antiprotozoal drugs. There are currently two treatments available that have been approved by the FDA for use in the US: Marquis, Protazil. To limit potential damage to CNS and reduce any inflammation, anti-inflammatory medicines are often prescribed. Using antioxidants can help with restoring the nervous tissue. To control or prevent this condition, owners are encourage to correctly store horse hay and feed, control the opossums in an area and quickly dispose of carcasses. These is not a vaccine for this available on the market.

EPM in horses is typically rare. Jim Rooney initially discovered this disease, which attacks the central nervous system of the animals, during the 1960s. The condition is caused by two parasites. There are many different signs and symptoms to be aware of for proper diagnosis. Horses that are treated early can be completely healed, although sometimes irreversible damage is done to the nervous system.




About the Author: