Equine Influenza Confirmed in Washington

Washington State Department of Agriculture (WSDA) officials confirmed on Sept. 10 that a Spokane County horse tested positive for equine influenza. The affected horse, a 4-year-old mare with an unknown vaccination status, started showing clinical signs of fever and nasal discharge on Sept. 6 and is reported to be affected and alive. A total of 10 horses were exposed to the virus.

Influenza 101

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.

Vaccination is an important and inexpensive way to protect your horse. US Equestrian requires proof that horses have had an equine influenza vaccination within the six months prior to attending organization-sanctioned competitions or events. Your veterinarian can help you determine what other vaccines your horse might benefit from.

In addition to vaccination, following strict biosecurity protocols can help reduce your horse’s chance of developing disease. Such measures include quarantining new equine arrivals at barns, disinfecting buckets and equipment, and preventing nose-to-nose contact between horses.