Nevus of Ota (oculodermal melanocytosis) in a dog.

A 5-year-old, female, spayed Rhodesian Ridgeback presented with ocular melanocytosis and skin hyperpigmentation involving the distribution of the first and second divisions of the trigeminal nerve on the right side of the face. The dermatomal pattern of the hyperpigmentation was similar to nevus of Ota or oculodermal melanocytosis reported in humans. This condition has been associated with increased risk of developing secondary glaucoma and melanoma transformation in skin, ocular, orbital tissues, and the central nervous system. The clinical investigation and description of oculodermal melanocytosis (nevus of Ota) are presented for the first time in the dog.