This study investigated three cases of transmissible venereal tumour in dogs. In Case 1, a 5‐year‐old male dog presented with an eye mass and penile growths, unresponsive to previous treatment. Case 2 involved a 4.5‐year‐old male dog with bilateral ocular masses and penile lesions. Case 3 featured a stray dog with ocular and skin masses. All cases were confirmed as transmissible venereal tumour through impression smear cytology. Treatment with vincristine sulphate resulted in significant remission, with complete recovery after the fourth injection. This study contributes valuable knowledge for veterinarians in diagnosing and treating transmissible venereal tumour in dogs, emphasising the significance of an approach to case management and careful consideration of the varying clinical manifestations of the disease.