Equine sarcoids are a good news-bad news kind of condition. The good news: These tumors themselves are typically not life-threatening. The bad news: They often develop on the head, abdomen, and legs, which can interfere with equipment and tack, and they are notoriously difficult to treat.

“The treatment of equine sarcoids, particularly large ones, remains challenging and can be frustrating for owners and veterinarians alike,” said study author Bettina Dunkel, DVM, PhD, Dipl. ACVIM, ECEIM, ACVECC, MRCVS, senior lecturer in equine medicine at the University of London Royal Veterinary College.

To test the efficacy of one treatment option—Newmarket bloodroot ointment—Dunkel and colleagues carried out a retrospective questionnaire-based study of 49 horses diagnosed with sarcoids.

Bloodroot ointment has cytotoxic and immune-modulatory effects on sarcoids, meaning it causes the abnormal cells to stop growing and shrink, Dunkel said. Still, the ointment’s full mechanism of action is still poorly understood, she noted