Abstract. Melanomas diagnosed in 29 cats over an 1 1 year period included 19 ocular (1 6 intraocular, three palpebral), five oral, and five dermal melanomas. Intraocular melanomas involved the ciliary body and iris in 12; the whole eye was involved in four. The average age of cats with intraocular melanomas was 1 1 years; the female : male ratio was 9 : 7. Histologically, eight intraocular tumors were mixed, six were epithelioid, and two were spindle cell. Ten of 16 cats (62.5%) with intraocular melanomas were killed because of the tumor at a mean of 156 days; four are living with no evidence of disease (average, 255 days). The mean time of death in cats with palpebral melanoma was 409 days. Metastasis occurred in 63% of cats with intraocular melanoma and all cats with palpebral melanoma. Four cats with oral melanoma were killed at a mean of 6 1 days; all had metastasis. Of five cats with cutaneous melanoma, one was killed with metastasis at 90 days; three cats were alive without evidence of recurrence or metastasis >365 days after surgery. Results of this study indicate that in the cat, ocular melanomas are more common than oral and dermal melanomas, and ocular and oral melanomas are more malignant than dermal melanomas, with higher rates of mortality and metastasis.Melanoma of any site is rare in the ~a t .~J l ,~~,~~ In a survey of necropsies of 3,145 cats, only one intraocular and three cutaneous melanomas were identified.25 Similar observations have also been made in surveys of neoplasms in cats. 12,27,35 The prevalence of intraocular melanoma compared to dermal melanoma in the cat varies in different studies, but most investigators report that cutaneous melanoma is more common than intraocular melanoma.yJ6,25,27 Melanoma is the most common histologic type of tumor among intraocular Uveal and cutaneous melanomas have been experimentally produced in the cat by injection of the Gardner strain of feline fibrosarcoma virus. 18, 31 In contrast to its rarity in the cat, melanoma is one of the most common tumors in the dog, mostly in the oral cavity. Melanoma is the most malignant tumor of the oral cavity in the d~g .~,~J~ Cutaneous melanomas compose 6% of canine skin tumors and are considered less malignant than oral m e l a n o r n a~.~>~.~J~ Ocular melanomas are rare in the dog but are the most common tumor of the canine eye; most are benign.9J0,2y Among other species, horses and swine are prone to cutaneous melanoma, but melanomas of the oral cavity and eye are rarely reported. 13,23, 34 The purpose of this report is to describe the clinical and pathologic findings in 29 cases of melanoma in the cat-19 ocular, five oral, and five cutaneous. Materials and MethodsMelanoma was diagnosed in 29 cats over an 1 1 year period from 1976 to 1986 at The Animal Medical Center. Diagnosis was made after enucleation and surgical biopsy. Clinical findings were taken from the medical records. Follow-up information was obtained by necropsy and personal contact with the owners. Tissue specimens were fixed in buffered 10% formali...

Twenty-three cats with malignant, nonhematopoietic tumors were treated with doxorubicin and cyclophosphamide. Fourteen cats had nonresectable tumors of the mammary gland, and nine had tumors of the oral cavity. Of the cats with mammary gland adenocarcinoma, seven cats had a partial response to treatment and seven cats had no response. Of the cats with oral tumors, one cat had a complete response, three cats had a partial response, and five cats had no response. All 23 cats are dead because of tumor progression or recurrence. Toxic effects were seen in 18 of the cats; most were transient and required no alteration in the treatment protocol. A high response rate combined with acceptable toxicity warrants further evaluation of combination doxorubicin and cyclophosphamide chemotherapy in cats with nonhematopoietic neoplasia. (Journal of Veterinary Internal Medicine 1988; 2:60-65)