The Washington State University College of Veterinary Medicine has confirmed a single horse with a rare neurologic form of Equine Herpes Virus (EHV-1).
Confirmation came late Friday and the horse has been in isolation in the Veterinary Teaching Hospital in Pullman, Wash., since its arrival yesterday at this time. The horse will be humanely euthanized today and its stall and surroundings will undergo terminal cleaning.
The horse in question is an 18 year-old quarterhorse mare from Newport, Wash., that has until it developed symptoms, been competing in rodeo events in the inland Pacific Northwest.
As required by law, WSU veterinarians have contacted the Washington Assistant State Veterinarian, Scott Haskell. His office and the Washington State Department of Agriculture (WSDA) will respond to the situation statewide.
The EHV-1 type was confirmed based upon clinical neurologic signs shown by the horse as well as testing by the Washington Animal Disease Diagnostic Laboratory (WADDL) in Pullman.
The virus is highly contagious and is spread via aerosolized secretions from infected coughing horses, by direct and indirect (fomite) contact with nasal secretions, and, in the case of EHV-1, contact with aborted fetuses, fetal fluids, and placentae associated with abortions. Disease can range from subclinical to the severe neurologic symptoms seen in the horse at WSU.
Horse owners are advised to contact their veterinarian to discuss vaccination and means for preventing EHV infections. The last outbreak affecting Washington horses came in May of 2011.