Malignant venereal tumors in dogs, occurring in their external genital organs, are transmissible between breeding dogs. The transmission occurs when the tumor cells are transferred from an affected dog to a healthy one during mating.
The tumors have a cauliflower-like appearance, but their sizes may range from less than 5mm to more than 10mm. They may occur singly or in groups. The tumor’s irregular surface may be inflamed and ulcerated. They may often bleed too. The tumor may spread from the genitalia to the nearby areas and to the mouth and nose when the dog licks the masses. It can spread to the eyes too.
Transmissible venereal tumors in dogs can be diagnosed by viewing the tumor cells through a microscope. These progressive malignant growths cannot be treated by surgery alone. Chemotherapy or radiation following surgical removal often gives good results, except when the tumor has become widespread.