Often called “grey horse tumors”, melanomas affect up to 80% of older grey horses, although they can also be found in individuals of all coat colors.
wo third of melanomas are cutaneous and localized under the tail, around the vulva and anus, around the genital organs or on the head. Melanomas can also be found in the ocular tissues, in the mouth and nasal passages. The clear majority of lesions are benign to start with, but up to 30% of them can become metastatic. In early stages, surgery can be successful but when melanomas become too extensive, surgical removal often becomes impossible.