Archive Case #119: Equine Melanoma

Clinical Clues

1. An older horse is presented for slowly enlarging skin nodules.
2. The masses have changed gradually over the past year without making the horse systemically ill.
3. Several nodules are clustered beneath the tail and around the perineum.
4. The horse is grey and the masses are darkly pigmented.
5. Pigmented skin tumours are especially common in ageing grey horses.
6. Equine melanoma frequently develops as black masses under the tail in older grey horses.

Diagnosis

Equine Melanoma

This case is most consistent with Equine Melanoma because the horse is grey and has typical slowly enlarging black perineal masses. The most important clues are the coat color and lesion location, which make a simple wart or sarcoid less likely.

Educational Use

Vetdle archive cases are educational veterinary games for diagnostic reasoning practice. They do not provide veterinary advice, diagnosis, treatment, or professional medical guidance.