Updated: Mar 13
Equine influenza is an acute, highly contagious inflammation of the upper respiratory tract caused by the influenza virus A/equi or A/equi 2. This disease is characterized by a dry cough lasting up to three weeks, a moderate to high fever (102-106*F; 39-41*C) for one to four days, and a serous nasal discharge for five to ten days. An affected horse will be depressed , have difficulty breathing, and exhibit muscular weakness and soreness.
In very old and very young horses, influenza may eventually involve the heart. As with any disease, equine influenza increases a horse's susceptibility to other infections, and complications such as a secondary bacterial infection or pneumonia will inhibit recovery.
Equine influenza spreads rapidly among susceptible horses. The disease occurs frequently in young horses after they have been moved to new surroundings and are exposed to a different group of horses.
Equine influenza may be prevented by the administration of influenza vaccines. Horses are less susceptible to the disease when they are healthy, well-fed, and protected from chills in draft free stalls.
A horse with influenza should be kept isolated and provided with individual feed and water buckets. To reduce irritating dust, hay and grain should be slightly dampened before they are fed. The animal should also be kept warm (with blankets if necessary) in a ventilated, dry wall. A minimum of ten days' rest after all signs of disease are gone is essential for a complete recovery.
If a horse with peracute equine influenza has great difficulty breathing, the veterinarian may administer oxygen therapy. In addition, a secondary bacterial infection will require antibiotic therapy. Corticosteroids are administered when shock is eminent, and the horse should receive a balanced electrolyte solution.