RESUMEN
This report describes a case of cutaneous transmissible veneral tumor (TVT) in a three-year-old male mongrel dog. Through clinical examination it was observed several cutaneous nodule ranging from aproximately 5mm to 4cm in diameter, some of which ulcerated, and several small and ulcerated nodules on the mucous membrane of the mouth. Through the Fine Meedle Aspiration (FNA) technique, the material of cutaneous nodules was sampled and processed for citologic and karyotypic exams. Upon citology, there was abundance of cells with round nuclei with coarsely granular chromatin and single distinct nucleoli, and cytoplasm containing several vacuoles. The karyotype showed a number of 58 chromosomes. Based on cytological and karyotypic findings extragenital TVT was diagnosed. The dog was treated with vincristine sulfate (Oncovin) in a dose of 0,025 mg/kg/weekly/IV. After the second aplication there was a reduction of 80 per cent of nodules with a complete cure at the end of the treatment