Warts are caused by the equine Papilloma virus. The warts usually begin as small, flesh-colored nodules that may turn gray and develop a cauliflower-like appearance. They tend to occur in groups on the muzzle, around the lips, nostrils, and eyes, and, occasionally, on the lower legs, the penis, and the vulva.

Warts often spontaneously disappear within approximately four months, but may last more than a year. Warts are contagious and transmission is usually by direct contact or by contact with environmental features, such as fence posts, feed buckets, or tack that have become contaminated by contact with a horse that has warts. The virus can also be transmitted by flies and other insects.

Symptoms

Small pink or gray nodules with rough edges that may appear in clusters.

Causes

Warts are caused by the equine Papillomavirus and are contagious.

Prevention

Good horse management is the best prevention. Since equine warts are contagious, isolating any horses that have warts is advised. Management practices to limit the spread of the virus include use of insecticides to prevent spread of the virus by flies and other insects and disinfection of feed troughs, water buckets, tack, fences, and stalls to prevent indirect transmission of the virus.

Treatment

Treatment of warts is not necessary unless they become infected or start to bleed. Since some warts may be confused with sarcoids, a biopsy may be necessary for diagnosis. Cryosurgery or chemical cautery by a veterinarian to remove troublesome warts may be advised.

If a large mass of warts interferes with the horse's activities, a veterinarian can prescribe the best solution to the problem. Various topical ointments and intravenous treatments, using EqStim, have shown some success in the treatment of warts. Most warts will regress as the horse develops an immunity to the virus, usually within three to six months.