Updated April 15, 2014
Virginia’s state veterinarian says a horse tested positive for Equine Herpesvirus Myeloencephalopathy (EHM), a neurological disease caused by equine herpesvirus (EHV-1.) The affected horse was located at a farm in The Plains, but was euthanized. Diagnostic samples were submitted after the steeplechaser experienced a fever for three days and showed neurological signs compatible with EHM.
Virginia Department of Agriculture and Consumer Services (VDACS) officials advise that strict biosecurity is the most effective way to minimize the risk of spreading the virus. The horse competed at the Piedmont Fox Hounds Point-to-Point Salem Course in Upperville, on Saturday, March 22, 2014, but organizers say there have been no reports of sick horses.
Horses from the farm did travel to two other states. State vets in the affected areas have been notified by VDACS. The Fauquier County farm that housed the index case remains under quarantine.
The potential for EHV-1 to cause Equine Herpesvirus Myeloencephalopathy is influenced by a number of factors and case reports vary from involving a single horse to very large numbers of cases.
VDACS officials say they are monitoring the situation and urge all horse owners in Virginia to minimize nonessential contact with other horses and to enhance their biosecurity practices on and off of the farm to prevent the spread of this and other infectious diseases. Horse owners should consult their veterinarians about specific ways to minimize the risk of EHV-1 infection on their farms.
The symptoms of EHM in horses may include a fever, nasal discharge, wobbly gait, hind-end weakness and dribbling of urine. The disease is often fatal. The virus is easily spread by airborne transmission, horse-to-horse contact and by contact with nasal secretions on equipment, tack, feed and other surfaces. Caretakers can spread the virus to other horses if their hands, clothing, shoes or vehicles are contaminated. EHV-1 poses no threat to human health.
VDACS recommends the following biosecurity measures for all horses that will come into contact with other horses at shows, trail rides, meets and other events:
•Minimize direct contact between assembled horses whenever possible.
•Clean and disinfect equipment, feed, tack, stalls and other surfaces that are shared between horses.
•Isolate and closely monitor horses that are returning from a show, trail ride or competition for a minimum of 14 days.
•Clean and disinfect caretakers’ hands, clothing, shoes and vehicles that may be contaminated by other horses or equipment.