An outbreak of equine herpes myeloencephalopathy (EHM), an unusual and potentially life-threatening form of equine herpesvirus (EHV-1) infection, is very big news for every horse owner, barn manager, and veterinarian.

Extremely contagious and easily spread, EHV-1 can cause a variety of problems, including respiratory infection, abortion, and in rare cases, paralysis and other neurologic complications. When EHV-1 causes neurological impairment, it is referred to as EHM.

Infected horses must be isolated, everything associated with those horses disinfected, and biosecurity protocols established as soon as possible, say University of Pennsylvania School of Veterinary Medicine (Penn Vet) experts. State authorities will assist with testing and must be notified, and quarantines should be put in place.

Because the horse and veterinary communities are so concerned about EHV-1, experts from Penn Vet’s New Bolton Center held an information session about the disease in June, attended by about 30 local veterinarians and others in the horse industry. Presenters included:

Drs. Helen Aceto (left) and Amy Johnson

Photo: University of Pennsylvania School of Veterinary Medicine's New Bolton Center

  • Helen Aceto, VMD, PhD, New Bolton Center associate professor of epidemiology and director of biosecurity;

  • Amy Johnson, DVM, Dipl. ACVIM, New Bolton Center assistant professor of large animal medicine