CORVALLIS, Ore. – Three weeks after diagnosing a horse with a form of equine herpes virus and suspending all elective surgical and medical services for horses and camelids, the Oregon State University College of Veterinary Medicine announced today that it is resuming normal operations.

EHV-1 is a naturally occurring virus that can cause serious neurologic illness in horses.

“There was no transmission of the virus to other horses within or outside of the hospital, so we are lifting quarantine and returning to normal operations effective immediately,” said Erica McKenzie, professor of large animal internal medicine. “The college thanks everyone for their patience and assistance during the quarantine period.”

EHV-1 can cause abortion in pregnant mares, which should be kept away from horses showing signs of the disease and also kept away from horses that have been in contact with exposed animals. Although a vaccine exists for EHV-1, it does not prevent infection and is not known to prevent clinical signs of neurologic disease related to the neurotropic form.

“Horse owners should be aware that although EHV-1 is not transmissible to humans, people can spread the virus on their hands and clothing to horses, alpacas or llamas if they are in contact with an infected horse,” McKenzie said.

Clinical signs consistent with infection with neurotropic EHV-1 often start with weakness in the hind limbs and can also include:

  • Uncoordinated, stumbling movements;
  • An unusual gait;
  • Weak tail tone;
  • Difficulty urinating, and dribbling of urine;
  • Inability of geldings and stallions to retract their penises;
  • Nasal discharge;
  • Fever (rectal temperature at or above 101.5 degrees Fahrenheit in resting horses).

Horses with any of the signs listed above should be isolated from other animals, and owners should contact their veterinarians immediately.

In rare cases, EHV-1 can cause blindness and central nervous system damage in alpacas and llamas.

Additional information regarding equine herpes virus and biosecurity recommendations are available from the American Association of Equine Practitioners at https://aaep.org/guidelines/infectious-disease-control/equine-herpesvirus-resources.

Media Contact: 

Steve Lundeberg, 541-737-4039