SALEM - The Oregon Department of Agriculture is notifying horse owners and other interested parties of a report of sick horses in Columbia County involving a single boarding stable near the town of Goble, between Rainier and St. Helens. The Veterinary Diagnostic Laboratory at Oregon State University in Corvallis has isolated the virus known as Equine Herpes Virus-1 (EHV-1). Sixteen of 19 horses at the stable have shown various signs of sickness. The majority of the horses have responded to treatment and are recovering. The virus is not a human health threat.
Officials emphasize that the disease is not connected to West Nile Virus. To date, there have been no reports of West Nile Virus in humans or animals in Oregon.
Equine Herpes Virus is common in the U.S. The virus can cause three different forms of the disease: 1) rhinopneumonitis (a respiratory disease of mostly young horses); 2) abortions in pregnant mares; and, 3) neurologic disease which can be a serious manifestation, especially in older horses.
EHV diseases are not regulated by ODA. However, the State Veterinarian's office has been assisting in the public awareness efforts. A self-imposed quarantine has been in effect at the stable. Area horse owners are being advised to keep their horses at home for at least a couple of weeks until the disease has been resolved.
There is a commercial vaccine available, ODA reported. Vaccination will generally reduce the severity of the respiratory form of this infection. Vaccination has not been shown to offer complete protection against the neurologic form of the disease. There is also a vaccine available which helps in prevention of abortion, which is another possible consequence of infection with this organism.
For purchase of vaccine and questions regarding vaccination, consult your local equine practitioner. For other questions, contact the State Veterinarian's office at ODA in Salem at (503) 986-4680.