A 4½ months old female Boxer pup, 6 years old Dachshund bitch and 10 years old Labrador dog were presented with extragenital transmissible venereal tumors. Based on the anamnesis, clinical symptoms and cytological examinations the cases were diagnosed as primary extragenital transmissible venereal tumors and histopathological examination of the specimens confirmed the diagnosis. The animals were treated successfully using Vincristine Sulphate intravenously at the rate of 0.025 mg/kg body weight.