Cryosurgery as treatment for chemoresistent TVT in a dog – case report

A seven-year-old 26 kg male dog presenting preputial serosanguineous discharge and a cauliflower-like mass on the penile bulb region was attended at a veterinary school hospital. The mass was hemorrhagic and friable. Cytopathological examination disclosed a plasmacytoid transmissible venereal tumor. Antineoplastic chemotherapy was initiated, associating piroxicam (0.3 mm/kg at 48 hour intervals) and vincristine sulfate (0.75 mg/m2 each seven days). Since no tumor regression was observed after eight chemotherapy cycles, doxorubicin was implemented as a new therapeutic protocol (30 mg/m2 each 21 days). No improvement was observed. Thus, three cycles of cryosurgery were attempted, using a Cry-Ac equipment with closed-circuit tip. Total remission of the tumor was observed 21 days post-surgery.