Support by FAPESP (Process 08/55534-1).

Electrochemotherapy is a promising therapy for local control of neoplasms, achieving high levels of remission without elevated financial and biological costs common to other treatments. Its mechanism of action relies on the electroporation phenomenon. Among the main characteristics of this therapy are the rare occurrence of side effects, the proven effectiveness for all solid neoplasms except for chondrosarcomas and osteosarcomas, the fast application and possibility of treatment of neoplasms refractory to other therapies. In this context, Cruel, a five year-old 36 kg canine white Pit bull, was diagnosed with disseminated squamous cell carcinoma in the back eleven months before arriving at Anhembi Morumbi University's Veterinary Hospital. This animal presented ulcerated lesions, four solid nodular lesions of 9, 8.5, 7.5 and 5 cm diameter and a plaque-shaped lesion of 15.2 x 8.9 x 3 cm. After all attempts of conventional treatment, electrochemotherapy was applied together with surgical excision of neoplastic lesions as a final attempt. Bleomycin was employed as antineoplastic agent at 15,000 UI/m² intravenously. Electrical protocol was of eight pulses of 100 μs at 1 Hz frequency and amplitude of 1079 V, applied with an electrode of equidistant needles disposed on a circumference of 0.83 cm diameter, with a central needle. Surgical excision of exophytic portions of nodules with electrocautery was associated to electrochemotherapy, which was applied at the base of neoplastic formations and on an area of 3 cm around the margin of the lesions. Due to the extent of the tumors, it was observed that the treatment would require three phases. The first phase would concentrate in three out of the four nodules; in the second, the last nodule and the plaque should be treated; and the third, the remaining ulcerated lesions would have due attention. The first nodules were, then, subjected to two sessions of electrochemotherapy, showing a discrete response after the first session and complete remission of the three nodules after the second session. The results are in accordance with therapeutic indexes described on the literature and confirm that the choice of therapy was appropriate, providing complete remission of treated lesions and the possibility of control of the disease in the animal.