Congenital malignant melanoma in two foals.

Two cases of congenital malignant melanomas in horses are described in this report. In each case, wide surgical excision of the mass was performed; no recurrence or metastasis was detected after a minimum of 15 months' follow-up. Melanomas are among the most common neoplasms of horses, but they typically develop in gray horses greater than 6 years old.