Influenza (Flu)

About Influenza

Equine influenza (flu) is an infectious disease that affects the upper and lower respiratory tract of the horse. Once a horse becomes infected with influenza the symptoms usually appear within 1 to 3 days and infected horses can spread the virus for 5 days thereafter. Influenza is spread by inhalation of the virus from the atmosphere, one horse coughing over another, and can spread rapidly through unvaccinated horses within a herd.

Symptoms Of Influenza

The first symptoms of influenza are often that the horse seems lethargic, depressed and develops a harsh, dry cough that usually lasts around 10 days. Other symptoms include a high temperature, lack of appetite, rapid breathing, enlarged glands under the lower jaw that result in a sore throat, clear discharge from the eyes and a clear nasal discharge that may become thick yellow or green. Diagnosis of influenza can be made by laboratory tests on nasal swabs.

Treatment Of Influenza

Due to its infectious nature any horse suffering from influenza should be isolated immediately and completely rested with feed modified accordingly. It is best to feed a soft feed and soaked hay as this can be swallowed without too much pain. Antioxidant feed supplements to help respiratory function and breathing can be beneficial. Horses will usually recover naturally within 2 to 3 weeks but occasionally complications such as lung damage can occur.

Prevention Of Influenza

Vaccination against influenza is advisable and vaccinations should be repeated annually. Where there is an outbreak of influenza on a yard it is advisable to give a booster to any horse that has not been vaccinated in the previous 6 months.