Symptoms of Horse Flu

Horse flu or equine influenza, a disease caused by a strain of Influenza A, primarily affects horses, donkeys, mules and other equine breeds. While older strains are considered to be extinct or existing in very low levels, the current strain is thought to be a mutation of avian flu.

  1. Spread and Incubation

    • The disease primarily affects the upper respiratory tract. It is highly contagious among unvaccinated horses. Incubation is usually one to five days.

    Early Symptoms

    • At the early onset of the flu, the horse will appear to suffer from depression. During this time, the horse will eat very little, and there will be signs of congestion, including a runny nose. Mucous will be clear. Some symptoms my look like colic. The horse's temperature may be as high as 105 degrees.

    Progression

    • After a few days, the equine's fever will go away. It may return, or come and go. As the upper respiratory symptoms progress, the horse's mucous will turn cloudy, and a cough will begin.

    Severity

    • Symptoms of the flu may be worse depending on the level of vaccination that the horse has had against the flu. While the vaccinations provide moderate protection against the flu and can mitigate symptoms, they are usually short lived. Booster shots should typically be administered every three to four months.

    Duration and Morbidity

    • In healthy horses, the disease will run its course within a week or two. In very young horses or equines with compromised immune systems, the disease is typically fatal.