Equine Flu

It may be an equine reportable disease in your state. Contact your state agricultural department for more information.

What are the symptoms?
Symptoms of equine flu include a high temperature (103-106deg F) lasting for one to five days and a dry, harsh-sounding cough that may linger for several weeks. There may be a clear, watery nasal discharge which may turn green or yellow as secondary infections develop. Also look for swollen lymph nodes under the jaw, a clear eye discharge, depression, lethargy, loss of appetite.

Pneumonia may develop in the very young and very old. This may be fatal in a few cases.

Where does it come from?

It's spread through nasal discharge, and the coughing and snorting that go with most chest infections. It is highly contagious. It’s most common in young horses, especially at racetracks, horse shows, and during transport and it is seasonally more prevalent in the summer and fall.

How is it diagnosed?

Blood tests and nasal swabs are necessary for definitive diagnosis, but consistent clinical signs and close proximity to a confirmed property is often enough.

How is it treated?

Infected horses must be kept at complete rest to avoid complications from secondary bacterial infections such as pneumonia. A veterinarian may prescribe an anti-inflammatory drug if the horse's fever is over 104F. Antibiotics may be prescribed when the fever lasts for more than three or four days or when purulent nasal discharge or pneumonia are present.

Fresh air and rest are important. Avoid dust in the environment, bedding and feed (particularly hay) to minimize the risk of bacterial infections of the lungs and airways.

Affected horses should be confined, and walked for short periods to maintain circulation. This should continue for at least the period of the fever and coughing, followed by gradually increasing exercise.

How is it prevented?

Equine influenza can be prevented by vaccination with the appropriate equine influenza virus strain but vaccinations have to be repeated every few months, as the immunity from the vaccine only lasts about three to four months. Vaccinated horses can still show symptoms, which these will be much milder than unvaccinated horses.

EI is a fragile virus and is easily killed with soap, detergent or disinfectant. The virus is also killed by exposure to sunlight for 30 minutes.

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