Nevada officials are reporting multiple cases of an often-fatal neurological form of Equine Herpesvirus Myeloencephalopathy in horses that have recently traveled in regional rodeo circuits, some of which have been in Utah.
“These recently reported cases are with horses that have traveled in junior high, high school and professional circuits,” said Dr. Barry Pittman, Utah state veterinarian at the Utah Department of Agriculture and Food. “We aren’t clear on all the specifics of the potential exposures in Utah but awareness, vigilance and reporting are important right now as we continue to trace origins and review potential contact that may have occurred.”
There are nine forms of EHM worldwide, only three of which are a health risk, and one form or another is found in nearly all horses by two years of age with little or no side effects. The most concerning form of it, found in Nevada, is fairly rare. Equine experts and veterinarians have not concluded why some contract it and others don’t.
EHM is usually spread by direct horse-to-horse contact through the respiratory tract and nasal secretions. It can also move indirectly through contact with physical objects that have virus contamination, and remain on them between seven and 30 days.
Symptoms can include fever, decreased coordination, urine dribbling, loss of tail tone, hind limb weakness, leaning against objects to find balance, lethargy and inability to rise. There are treatments for EHM, but they are not always effective and vaccines being used are limited in their scope of prevention.
“We’re advising horse owners to limit travel with their horses if possible, check ahead with rodeo or event personnel for any known cases or exposures at their facility; practice active bio-security; don’t share tack, feed or water buckets, grooming equipment, stalls or trailers; and always clean and disinfect all of the previous on a regular basis,” said Pittman.
Owners with a horse that has been exposed to the more serious form of EHM and is exhibiting symptoms are urged to contact their veterinarian and they should report to the State Veterinarian’s office if they suspect EHM.