Intraocular melanoma with multiple metastases in a cat.

An 11-year-old cat with an intraocular melanoma was treated for 2 years for the secondary effects of the tumor (glaucoma, exposure keratitis) before enucleation was required. One year after enucleation, the cat was examined because of labored breathing. The cat was thin, appeared depressed, and had signs of respiratory compromise secondary to pleural effusion. Treatment was not instituted, and the cat was euthanatized. Metastasis of the primary melanoma to the lungs, pericardium, parietal pleura, mediastinum, hilar lymph nodes, diaphragm, liver, and omentum was confirmed at necropsy. Intraocular melanomas in the cat have been implicated to have a greater malignant potential than those in the dog; however, few cases have been reported with long-term follow-up information.