Melanomas are tumours of the skin in horses. Unlike in people they are almost always benign and cause few problems Many horses have melanomas but grey horses are much more prone to have them. Most elderly grey horses have at least one melanoma. Only very rarely do melanomas become cancerous and spread to other parts of the body but when they do become so the outlook is very poor.
Melanomas are most commonly found on the underside of the tail, around the anus and vulva, around the sheath and on the head.
Treatment of melanomas is normally only necessary when they become ulcerated which sometimes happens when they become too large underneath the tail.
Faq’s about melanomas: www.freevetadvice.co.uk/melanoma.htm