Dr. Sarah Colmer of New Bolton Center says the outlook for a horse with equine protozoal myeloencephalitis (EPM) depends largely on how severely it’s affected. Mild cases—such as horses showing subtle incoordination—often recover well. But horses with severe signs, like difficulty standing or swallowing, face a much tougher road. Because the disease and the body’s own inflammatory response both contribute to nerve damage, predicting recovery can be challenging. In general: the milder the signs,

What is EPM?