Help, My Horse Has Warts!

Warts are small, harmless skin tumors that often appear on the muzzles of young horses. Because owners consider them unsightly, warts are a frequent cause of veterinary consultations. Possible treatments include surgery and injections of wart-derived vaccine, but the easiest course of action is simply to wait a few months and allow the warts to go away on their own. In virtually all cases, the warts do not cause scarring or skin discoloration.

Caused by several strains of papilloma virus, warts are usually found in horses that are less than three years old. They often form on skin that has been compromised or stressed by sunburn, minor injuries, or insect bites. A horse might have one or many warts, most of which will spontaneously disappear within six to nine months after they show up. After a round of warts, most horses are immune to further wart development, though an occasional older horse is affected.

The virus that causes the growths can be spread to other horses by direct nose-to-nose contact or on tack, grooming supplies, water buckets, or human hands. If one horse in the barn has warts, handlers can minimize the chance of spreading the virus by frequent hand-washing and using a separate set of tack and equipment for the infected horse.