Equine Influenza

Equine influenza (EI) affects horses, donkeys, mules and other equine relatives. Other names for the disease include epizootic cellulitis, stable pneumonia and shipping fever.

  1. United States

    • A major outbreak of EI in the United States began in 1872. The outbreak, called "The Great Epizootic," affected over 80 percent of horses in 33 states.

    Spread

    • Sharing water or feed buckets can spread the disease.

      Respiratory secretions such as sneezing or coughing and contaminated objects spread EI. A horse is contagious for up to 10 days after the symptoms are gone. However, a horse can have EI but never show symptoms and still pass the disease, according to the American Veterinary Medical Association (AVMA).

    Risks

    • Horses between one and five years old and those in contact with many other horses are at the greatest risk of getting EI, according to the American Association of Equine Practitioners (AAEP).

    Incubation and Symptoms

    • From infection to symptoms is typically one to three days, but may be up to seven days. Almost all exposed unvaccinated horses will get the disease. Symptoms include fever, coughing, nasal discharge and swollen lymph nodes.

    Treatment and Prevention

    • With rest, most horses recover within two weeks. Antibiotics and medicine for fever may be necessary if an infection occurs. Vaccinations are available that reduce infection or decrease symptoms. Boosters may help prevent infection during an outbreak, according to the AAEP.

    Equine/Canine Contamination

    • Equine influenza, spread to dogs in 2004, is the source of canine influenza, according to the Centers for Disease Control.