A sarcoid is a tumor of the skin of horses, donkeys and mules, thought to be caused by a virus infection. They tend to appear as wart-like growths with either a thick crusty surface or an ulcerated area of the skin that will not heal and bleeds when touched. It is the most frequently diagnosed tumor in horses. They have not been known to spread to internal organs, but veterinary help is esssential because they are notoriously difficult to heal and frequently reccur.
Sarcoids occur at any age but are more common in young adult horses. These tumors may be single or multiple and , although they occur most frequently on the head, limbs and abdomen, they can occur anywhere on the body including the site of an new injury or even healed wounds. Even though all breeds are affected, a generic predisposition to sarcoid development may exist. Appaloosas and Arabians may be at greater risk and American Standardbreds at lower risk to develop sarcoids. There is no gender, coat color, seasonal or geographic bias for their occurrence.
There are many approved methods of treatment some of which include surgical excision, cryotherapy (freezing), immunotherapy, radiotherapy, and laser therapy being the more generally used. Treatments may have to be repeated.
If you want more detailed information about this condition, try this site at Liverpool University - http://pcwww.liv.ac.uk/sarcoid/
Sarcoids occur at any age but are more common in young adult horses. These tumors may be single or multiple and , although they occur most frequently on the head, limbs and abdomen, they can occur anywhere on the body including the site of an new injury or even healed wounds. Even though all breeds are affected, a generic predisposition to sarcoid development may exist. Appaloosas and Arabians may be at greater risk and American Standardbreds at lower risk to develop sarcoids. There is no gender, coat color, seasonal or geographic bias for their occurrence. 
