Common Equine Skin Cancers
Be on the lookout for the three most common skin cancers afflicting horses and contact your veterinarian promptly if you find suspicious lumps or bumps.
Skin cancer is the most prevalent type of equine cancer, accounting for up to 80 percent of all cancers reported.
Sarcoids are the most frequently diagnosed type, with squamous-cell carcinoma the next most prevalent, followed by melanoma.
Learning about these cancers and what to watch for will allow you to closely monitor your horse and seek veterinary advice promptly if you notice something that looks abnormal. While skin cancer poses a health risk for our beloved horses, many cancers are treatable, and early diagnosis will improve the horse’s quality of life and chance of survival.
Sarcoid Tumours
The most common equine cancer, sarcoid tumours account for approximately 40 percent of all equine cancers. They can occur in any breed and at any age, typically developing in horses three to six years old. Sarcoids can be found anywhere on the body, often on the head, near the genitals, and on the underside of the abdomen. They may also form at sites of previous injury or scarring. Although non-malignant, these tumours can spread aggressively, occurring as single or multiple lesions ranging from small and wart-like to large, ulcerated, fibrous growths that can impact quality of life. Bovine papillomavirus is believed to be involved in the development of sarcoid tumours, although its precise role is not known.
The Merck Veterinary Manual describes the six recognized clinical varieties:
- Occult — flat, gray, hairless, and persistent, often somewhat circular;
