Sarcoids usually appear as large, cauliflower like warts. They are the most common type of tumor in horses. The specific cause of sarcoids is not known, but a virus is thought to be involved. Occasionally a group of horses has a high incidence of sarcoids, but sarcoids are not contagious. Sarcoids may occur at sites of previous trauma, possibly allowing a causative virus to grow at the injured site. Heredity may also play a role. Certain individual horse lines or breeds may have a higher incidence of sarcoids. The tumors may respond to vaccines and other immunostimulants.
Sarcoids can have quite large, flat bases and can occur in areas that are difficult to treat, such as on the ears, around the eyes, and on the coronet. Those occurring over muscular areas are easier to treat. There are many different treatments for sarcoids, but they often recur after treatment. Recurrence depends on how long the sarcoid has existed, and the number and size of the sarcoid(s). After previous removal, they are more resistant to complete removal. Keeping your horse in a clean environment and reducing insect contact is important.
This horse had been treated previously by surgical removal and by medicinal therapy. Unfortunately the tumor became very aggressive and started to get out of control. The tumor was surgically be de-bulked, treated with cryotherapy (freezing the tumor tissue) and the horse was also given immunostimulants. This horse did well for quite some time, he began eating again and picked up in both weight and attitude. Unfortunately, despite our best efforts, the tumors re-occurred and the horse was euthanized for human purposes.