Officials at the Washington State Department of Agriculture (WSDA) confirmed on Nov. 21 that two Snohomish County horses tested positive for equine influenza, with an additional 28 horses exposed.
The positive horses included a 12-year-old grade mare and a mixed-breed suckling foal, both of which were unvaccinated and began experiencing clinical signs of coughing, fever, and nasal discharge on Nov. 18. Both horses are reported as recovering.

The attending veterinarian is monitoring other horses in the barn, all of which had been vaccinated and have not shown signs of illness, during the voluntary quarantine.

About Equine Influenza

Equine influenza is a highly contagious respiratory disease that affects horses, ponies, and other equids, such as donkeys, mules, and zebras. The virus that causes it is spread via saliva and respiratory secretions from infected horses. Horses are commonly exposed via horse-to-horse contact; humans that pick up the virus on their hands, shoes, or clothes; tack, buckets, or other equipment; and aerosol transmission from coughing and sneezing.

Clinical signs of equine influenza infection can include a high fever (up to 106°F); a dry, hacking cough; depression; weakness; anorexia; serous (watery) nasal discharge; and slightly enlarged lymph nodes. Consider monitoring your horse’s health at shows by taking his temperature daily, which can help you pick up on signs of infection early and take appropriate measures to reduce disease spread.