Evaluation of the cytotoxic response in the treatment of transmisible venereal tumor in dogs by using bleomicin or vincristine

The objective of this work  is to evaluate  the efficiency of bleomecyne sulfate via subcutaneous or intratumural in the treatment of this tumor, comparing the results reached with the obtained from the use of vincristine sulfate. For this purpose, it was selected 15 dogs which confirmed TVT wounds through cytological and/or histological examinations, therefore they were divided in three in group of five animals. The patients of control group (G1) have received a dose of 0,75 mg/m 2 /IV of vincristine sulfate. The patients of group G2 have been submitted to a treatment using a dose of 0,4UI/kg of bleomycin sulfate intratumoral, while the dogs of group G3 have received a dose of 0,4UI/kg of bleomycin sulfate subcutaneous. In the patients  of group G1 the cytoreduction happened gradually according to the sections, and in four of the five dogs there was  a complete remission after the fifth session of antineoplastic chemotherapy, resulting in a meaningful statistic difference (p<0,05) when compared with the results of group G3. However, the dogs of group G3 presented cytoreduction only after the first session, which  was not observed in second, third and fourth sessions, the moment that the tumors kept stable, and started to growth in the fifth and sixth application. The dogs of G2 have presented an important remission after the firth session, however, in the second and the third and fourth session the tumors have kept stable and after the fifth and sixth applications have presented a slightly regression. The best result, were observed with the administration of vincristine sulfate, however, new studies must be accomplished to improve the efficiency of bleomycin sulfate in the treatment of TVT. An option that must be better studied is the use of intratumural bleomycine in cases of TVT that have already been treated and have presented resistance to the use of vincristine sulfate.