By: Dr. Lydia Gray

What is it?

Warts are small growths on the muzzle of young horses caused by the papilloma virus. They are usually only seen on horses four years of age and younger because the immune system of the young horse is not yet fully developed. Most adult horses have developed immunity to the virus. Because warts are caused by a contagious virus, infected horses (and their tack and equipment) should be kept separate from other horses to limit spread of the condition.

What can be done about it?

Since warts usually go away on their own in six to nine months, no treatment is generally needed unless the warts are in an area where they interfere with tack or have been irritated and developed into open sores. Many people believe removing a few warts by pinching them off helps speed up the process but research has not supported this belief. Likewise, a vaccine made from a horses own warts does not seem to cause them to go away any sooner either.

What else do I need to know?

The same virus that causes warts on the muzzle of young horses also causes ear papillomas, or aural plaques, in adult horses. Just like with warts, the best treatment is usually to leave them alone unless they are growing large or obviously causing the horse discomfort. Of course, any skin condition should be examined by a veterinarian to confirm the diagnosis and rule out a more serious problem such as sarcoids or sarcoma.


SmartPak strongly encourages you to consult your veterinarian regarding specific questions about your horse's health. This information is not intended to diagnose or treat any disease, and is purely educational.