There have been no additional cases of horses infected with equine herpesvirus-1 (EHV-1) since the June 1 reported infection of a 14-year old Quarter Horse gelding in Marion County.

The horse was treated at Oregon State University College of Veterinary Medicine’s Large Animal Hospital and returned to his stable, which remains under quarantine. All horses located at the stable remain under active observation by owners and their veterinarians for clinical signs of disease.

All eight quarantines associated with previous EHV-1 cases in Oregon have been released.

Herpesvirus is highly contagious among horses and can cause a variety of ailments in equids, including rhinopneumonitis (a respiratory disease usually found in young horses), abortion in broodmares, and myeloencephalopathy. In many horses, fever is the only sign of EHV-1 infection, which can go undetected