Equine Influenza

by Sharon Hopkins

Equine Influenza can be described as one of the most common diseases to affect the respiratory tract in horses. Also known as Horse Flu, this condition is mainly caused by two strains of virus, which are Equine 1 or H7N7 and Equine 2 or H3N8. The Equine 1 virus has the tendency to affect the heart muscle while Equine 2, the more severe virus of the two, is more systemic. Horse flu is endemic, as it has been known to affect the equine population throughout the world, including the US.


Equine influenza can easily spread from one horse to the other. Therefore, one infected horse can cause the virus to circulate even in a large group. Some of the factors that increase a horse’s risk of contracting this disease include:
  • Being between the ages of 1 and 5
  • Frequent contact with a large number of unvaccinated horses
  • Exposure to infected waste material in stables

This disease spreads rapidly among horses and its incubation period is relatively short, between one and five days. The viruses that cause equine influenza can cause the species barrier and cause an epizootic disease in canines and humans too.


There are several signs and symptoms that a horse may experience after exposure to the disease causing virus. Given below are some of the most common symptoms of equine influenza:

  • High body temperature
  • Hacking cough
  • Runny nose
  • Lethargy
  • Depression
  • Reluctance to eat or drink
  • Weight loss

The severity of the symptoms may vary from one horse to the other. In most instances, the signs disappear within two to three weeks.


The treatment path for equine influenza may vary from one horse to the other, depending upon the severity of the condition and its symptoms.

In case your horse has not developed any complications, he probably needs nothing more than supportive care and a lot of rest. Make sure that your horse rests for at least 2 to 3 weeks, in order to regenerate the mucociliary apparatus.

If the horse is suffering from high fever which is more than 104 Degrees F (40 Degrees C), the treatment may include NSAIDs. You may need to give your horse antibiotics, in case his fever persists over 3 to 4 days. Antibiotics may also be prescribed for complications like pneumonia and purulent nasal discharge.


As a horse owner, you can reduce the risks of equine influenza by following a few preventative measures.

There are several commercial vaccines that can immunize your horse against equine influenza. A vaccination schedule generally involves the primary vaccine followed by booster shots. Do speak to your vet about this, for more information.


  1. http://www.dpi.nsw.gov.au/agriculture/livestock/horses/health/general/influenza

Warning: The reader of this article should exercise all precautionary measures while following instructions on the home remedies from this article. Avoid using any of these products if you are allergic to it. The responsibility lies with the reader and not with the site or the writer.
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