Photo: David Powell, BVSc, MRCVS, FRCVS
A horse from eastern Oregon that was referred to Oregon State University's (OSU) veterinary teaching hospital in Corvallis has been diagnosed with equine influenza virus, a highly contagious respiratory disease in horses that typically is not fatal.
The 4-year-old Quarter Horse mare, who recently arrived in Oregon from Texas, has been placed in isolation and is being treated. The mare was purchased at a sale in Hermiston, Ore., last weekend and several horses that were in close contact with her also have developed signs of illness, though they have not yet been diagnosed with equine influenza virus, officials say.
Equine influenza is the most common contagious respiratory pathogen for horses and most animals fully recover, an OSU statement read, adding that young, elderly or pregnant animals are more at-risk for viral diseases such as equine influenza.
"Equine influenza is especially dangerous to foals and the foaling season just started," said Keith Poulsen, DVM, Dipl. ACVIM, of the Lois Bate Acheson Veterinary Hospital in OSU’s College of Veterinary Medicine. "The virus can be spread by direct contact with nasal discharge, or when aerosolized from coughing."
The Large Animal Internal Medicine and Surgery Services program at OSU's College of Veterinary Medicine is working with the state veterinarian’s office to inform veterinarians and horse owners about the disease.
Poulsen said the first clinical sign in horses is typically a fever, followed by cough, nasal discharge and lethargy. Horses with a fever of greater than 102.5 degrees should be seen by a veterinarian. Horse owners should also consult with their veterinarian about vaccinations, he added.
Infected horses can "shed" or transmit the virus for up to 10 days after incubation. Horses that show signs of the disease should be isolated from other horses for 10 days after clinical signs first appear.
"The good news is that many disinfectants can easily kill the equine influenza virus, and thoroughly cleaning stalls and equipment can help prevent the virus from spreading," Poulsen said.
The infected horse will remain at OSU in isolation until she fully recovers. As an added precaution, the OSU hospital is only accepting equine patients requiring emergency treatment until Wednesday, Feb. 27. Horses being referred for elective surgery, lameness, or non-emergency conditions will be delayed until after Wednesday.