May 4, 2015--Four Oregon horses have now tested positive for Equine Herpes Virus (EHV-1) with two of the horses showing neurological symptoms, according to the Oregon Department of Agriculture. It was confirmed last week that a Marion County horse had tested positive for EHV-1 and had developed neurological symptoms. The second horse that developed neurological symptoms resided at a stable in Polk County with about 40 other horses and was taken to the Large Animal Hospital at Oregon State University’s College of Veterinary Medicine over the weekend. The Polk County stable has been placed under quarantine and the remaining horses are being monitored by the stable manager and a veterinarian. In addition to the Polk County stable, two Marion County farms remain under quarantine due to exposure to EHV-1. The infected horses and other horses exposed at the quarantined facilities attended an Oregon High School Equestrian Team (OHSET) meet at the Linn County Fairgrounds on April 16-19. ODA is currently investigating the potential of any additional exposures at this time. In addition, ODA is working to notify owners of horses that have been potentially exposed and has notified Oregon equine veterinarians.