Treatment of canine transmissible venereal tumor using vincristine sulfate combined with L-asparaginase in clinical vincristine-resistant cases: A case report

Abstract

Three female mongrel dogs were cytologically diagnosed as transmissible venereal tumor (TVT) and had clinically developed resistance to vincristine treatment. One dog was treated with four treatments of 10,000 IU/m2 body surface area of L-asparaginase combined with 0.025 mg/kg body weight of vincristine sulfate every two weeks while this combination was administered to the others once a week for four weeks and only vincristine sulfate once a week for four treatments. Both treatments resulted in a complete remission. Side effects such as gastrointestinal upset, diarrhea, depression, and decrease in appetite were observed in the dogs administered with the later protocol. Hematologic disturbance was observed in one out of two dogs showing leukopenia three weeks after the treatments. Although the complete regression of tumor was observed in both treatment courses, two-week treatment interval is recommended to avoid undesirable effects.