Horse Flu Information

Horse flu, more properly called equine influenza, is often blamed for any respiratory illness a horse contracts. Equine viral arteritis, equine adenovirus and rhinovirus and rhinopneumonitis are often confused with equine influenza, all have symptoms similar to equine flu. Viral arteritis, influenza and rhinopneumonitis can be prevented with a series of vaccinations; all can be prevented with good hygiene.

  1. What is equine influenza?

    • Equine influenza consists of several flu viruses that attack the respiratory system of horses. These are not the same flu viruses that effect humans.

      The viruses that cause equine influenza are more stable than the viruses that cause human 'flu. This means that equine flu viruses do not mutate from year to year and the vaccines used today are similar to the ones used 20 years ago.

      Horses may become very ill and show all the symptoms of equine flu or they may be carriers. This means an apparently healthy horse will shed (or spread) the virus, infecting all of his stablemates.

      Equine influenza, by itself, is not fatal. However, a horse that contracts equine flu has a compromised immune system and is vulnerable to other, more serious, respiratory infections like pneumonia.

    How it is spread

    • Equine flu is spread by inhalation and contact with the secretions (slobber and mucus) of infected horses.

      As infected horses cough and sneeze, the virus (encased in water droplets) is spread into the surrounding air, sometimes up to 14 feet. Uninfected horses inhale the droplets and may develop equine flu if: they have never been vaccinated; the immunity they received from a flu vaccination has lapsed; or their health is compromised by another serious illness.

      Equine flu can also be spread from horse to horse by poor handler hygiene. Using the same equipment on multiple horses is common in busy stables. Equine flu viruses will live in slobber and snot left on tack, buckets, halters, bits, bedding, wood and a handler's clothing or hands.

    Symptoms

    • Horses will develop symptoms one to five days after exposure.

      A high fever that lasts for three to five days is the first symptom. This is followed by a persistent dry cough. Nasal discharge and swollen lymph nodes under the jaw also occur with the cough.

      Horses may not want to eat or drink while they are running the fever. They may also develop muscle stiffness, apathy and runny eyes.

      The primary symptoms of equine flu last three to seven days, however your horse may still exhibit coughing and nasal discharge for several weeks.

    Treatment

    • Rest and supportive care are the best treatments for equine flu.

      Stall rest in a dry well ventilated stall isolated from other horses is required. Do not close the barn up; air flow is essential to dissipate the virus. Blanket your horse if it is cold and wrap his legs with polo wraps to prevent edema (fluid buildup in the legs). Give your horse plenty of high quality grain and hay and provide clean water.

      Bute may be used to bring down fevers and eliminate muscle stiffness.

      Antibiotics and steroids are only given to horses that develop secondary respiratory infections like pneumonia.

      The minimum recuperation period is three weeks. Add one additional week of rest for every day of fever over three days. Five days of fever means five weeks of rest. This rest period allows tissue destroyed by the 'flu virus to regenerate.

    Prevention

    • Vaccinate your horse against equine influenza yearly. Vaccinate your horse every six months if you participate in horse shows, sponsored trail rides or board at a busy stable.

      Quarantine new horses for ten to fourteen days. Horses will show symptoms of the virus during this period and if the horse is a carrier he will have finished shedding the virus.

      Sterilize, or at least wash with hot water, equipment shared by horses. Wash your hands frequently and always handle healthy horses before handling sick horses.