Transmissible Venereal Tumor in Dogs

Transmissible venereal tumors are a highly unusual form of cancer in dogs. Cancer is a general term for uncontrolled cell growth which leads to the development of abnormal masses of tissue called tumors. Most forms of cancer arise spontaneously from within the body. Transmissible venereal tumors are contagious and spread between dogs through skin to skin contact, which is remarkably different from other forms of tumor development.

Transmissible venereal tumors are seen more often in mixed-breed dogs, dogs that are still sexually intact, and stray or free-roaming dogs. TVT is more prevalent in tropical and subtropical climates, but is documented worldwide. It is often treatable and is not often metastatic leading to an overall positive prognosis.

If the tumors are not around the genitals, they may appear as cauliflower-like masses around the affected area, often the mouth, which may bleed or ulcerate.

The main cause of transmissible venereal tumors is through skin-to-skin contact. This is most often sexual contact but can involve sniffing, licking, or contact during birth.

Masses are localized generally around the genitals. This can be one or more growths and is often accompanied by bleeding, bruising, or abnormal thickening of the surrounding skin. This may be accompanied by frequent licking of the affected area and general signs of physical discomfort.

After a physical examination and medical history, diagnosis of transmissible venereal tumors is confirmed through a biopsy or cytology.

The primary method of treatment for this tumor is chemotherapy as surgery alone can lead to recurrence. Complete surgical excision and radiation therapy can also be used depending on the location and specific characteristics of the tumor. In very rare cases, the tumor can undergo spontaneous regression.

With treatment, prognosis is generally good with no incidence of recurrence. In cases where chemotherapy and radiation are not used, recurrence is more likely.

In cases of metastasis, prognosis is mixed and depends on the location of the secondary cancers and the spread within the body.

Transmissible venereal tumors are contagious to other dogs. They are transmitted through skin-to-skin contact activity and can be prevented by preventing physical contact with an infected dog. Spaying and neutering intact dogs reduces this risk by reducing mating activity.

Transmissible venereal tumors are uncommon in dogs in North America, but are fairly common in other parts of the world.

• Chemotherapy
• Radiation
• Surgery