Equine Protozoal Myeloencephalitis (EPM) in Horses

Prognosis for Horses With EPM

With treatment, up to 60 percent of horses with EPM will improve, but less than 25 percent recover completely. Relapses are also common for as long as two years after the initial treatment with anti-protozoal medications.3 Still, your horse has a good chance of regaining at least some of its former health with prompt intervention. If left untreated, the prognosis for horses with EPM is very poor, as the condition can deteriorate to seizures and death.

How to Prevent Equine Protozoal Myeloencephalitis

There is no vaccine for EPM. Prevention consists of minimizing the presence of opossums on your property as much as possible. Wire-mesh fencing can help keep these marsupials out of your stable area, although because opossums are good climbers, you may have to resort to electrified fencing if they are especially persistent.

Opossums are generally looking for food and are not picky eaters. They will raid trashcans, eat dog food that's left outside, consume your horse's grains, and even eat carcasses of dead animals that they find on the road or within your property. It's essential that all food stores be secure and any animal carcasses buried promptly. Clean up any spilled feed right away, and make sure trashcans have tightly fitted lids.

If opossums make their home on your property, they should be humanely trapped and removed. Other options are motion-activated lights or sprinklers, which can frighten the animals away.