Surgical Management of Canine Transmissible Venereal Tumor with Adjunctive Chemotherapy Combination

One male and a female 2-year-old Neapolitan Mastiff dogs weighing 41 and 40 kg, respectively, were presented to the University Veterinary Teaching Hospital, Jos, Nigeria, with complaints of continuous bleeding from the prepuce and vulva which were first observed about 2 months before presentation. Clinical examination revealed preputial bleeding of the male dog and serosanguinous vulva discharges with the presence of palpable masses with multiple nodules that were cauliflower-like. Cytological evaluations of smears from preputial and vaginal swabs revealed characteristic round cells with large eccentric nuclei, large nuclear-cytoplasmic ratio, and intracytoplasmic vacuolations as well as anisocytosis and anisokaryosis. Based on these cytological features, a diagnosis of canine transmissible venereal tumor (CTVT) was made in each case. Blood samples were collected for hematology and clinical chemistry. Debulking of the masses was carried out under general anesthesia using atropine sulfate and chlorpromazine as pre-anesthetics and Ketamine hydrochloride as induction and maintenance anesthetics. Following debulking, the resulting defect was reconstructed and the surgical wound was managed by daily wound cleaning and the administration of vincristine sulfate (0.025 mg/kg) slowly intravenously, ivermectin (0.3 mg/kg) subcutaneously, and piroxicam (0.3 mg/kg) and 20% amoxicillin (20 mg/kg) intramuscularly. There were no observed known vincristine sulfate-associated adverse effects as the dogs recovered and were discharged 3-week post-tumor debulking with no recurrence within 6 months of follow-up examinations. The debulked mass histologically showed several sheets of round neoplastic cells with prominent nuclei, mitotic figures, and infiltrating lymphocytes. Based on these findings, a diagnosis of CTVT was further confirmed. The hemogram showed moderate leukocytosis at day 1 in the bitch with a mild left shift at days 1 and 14 while clinical chemistry showed a marked increase in alkaline phosphatase, moderate increase in serum creatinine, and mild hypoproteinemia. In conclusion, management of CTVT with adjunctive vincristine sulfate and ivermectin combination resulted in complete healing with amelioration of known associated adverse effects.