Canine Transmissible Venereal Tumor (CTVT) is a type of cancer that affects dogs, specifically their reproductive tissues. It is unique because it can be transmitted between dogs through direct contact, often during mating. CTVT is caused by cancer cells that can survive outside the original dog and infect other dogs, making it a contagious form of cancer. The tumor typically appears as growths on the genitals or around the mouth and can vary in size. While CTVT is not usually life-threatening, it can cause discomfort and requires treatment, which may include chemotherapy or surgical removal. Early detection is important for effective management.