On Thursday, February 12, 2015, the Virginia Department of Agriculture and Consumer Services (VDACS) was notified of a horse in Loudoun County that tested positive for Equine Herpesvirus Myeloencephalopathy (EHM), a neurological disease of horses caused by Equine Herpesvirus-1 (EHV-1).

On February 5 that horse exhibited a fever and was not eating or drinking. Even though it never showed neurological signs, the owner took the horse to the Marion duPont Scott Equine Medical Center (EMC) in Leesburg. There they tested for and quickly diagnosed EHV-1. The horse is under quarantine there and is recovering. A second horse from the same farm exhibited a fever but no other signs. As a precaution, it is also under quarantine at the EMC and VDACS is running tests at its Regional Animal Health Laboratory in Warrenton.

Dr. Richard Wilkes, State Veterinarian with VDACS, stressed that the horses were admitted directly into the isolation area at Marion duPont Scott. At no time were these horses in the general hospital area. The EMC is confident that their bio-security protocols will contain the virus to the isolation area.

Thirty-three other horses from the same farm are under quarantine on the farm premises in Loudoun County. None of them have shown any signs of EHV-1, but will be monitored at least through February 26. No horses from this farm have been at events during the incubation period for the virus.

VDACS began an epidemiological investigation on February 13 and will continue to monitor the situation. The Department will provide regular updates on its website – vdacs.virginia.gov/animals/ehv.shtml – and on Facebook and Twitter at facebook.com/VaAgriculture and twitter.com/VaAgriculture/.

On February 6, VDACS announced that a horse in western Albemarle County had tested positive for EHV-1. That horse has been under quarantine for a week and continues to improve. There is no known connection between the Loudoun and Albemarle horses.

More information on EHV-1 is available at vdacs.virginia.gov/animals/ehv