Transmissible Venereal Tumor (TVT) in Dogs

Overview of Canine Transmissible Venereal Tumor (TVT)

Transmissible venereal tumor (TVT) is a tumor of the external genitalia. It is a disease entity of sexually intact dogs, and it is spread by sexual activity or social behavior. Females are slightly more prone to tumor development than males. It occurs more commonly in young dogs.

What to Watch For

Signs of transmissible venereal tumor in dogs may include:

• A visible mass on the penis or vagina
• Blood dripping from the penis or vagina
• Frequent licking of the genitalia
• Similar masses in the mouth or nose (tumors can spread to these sites from direct contact)

Diagnosis of Transmissible Venereal Tumor in Dogs

• History and physical exam. It is important to know the animal’s sexual history. Physical exam should reveal a reddened, possibly bleeding, lobulated tumor. This may not be apparent without careful examination, as it may be covered by the sheath of the penis or the vulva.
• Fine needle aspirate. Aspiration of cells from the mass using a needle and syringe usually yields a diagnosis. The cells are examined microscopically to characterize the tumor type.
• Biopsy. Definitive diagnosis may require a biopsy of the mass if the fine needle aspirate is not conclusive.
• Complete blood count and biochemical profile. These are routine blood tests that should be performed prior to medical treatment of the tumor. They should be normal in animals with TVT.

Treatment of Transmissible Venereal Tumor in Dogs

• Chemotherapy with the drug vincristine is the treatment of choice and is usually curative. Several treatments may be required.
• Surgical removal of small tumors may be possible, but they will often recur following surgery.
• Radiation therapy may also be curative.

Home Care and Prevention

Monitor for response to therapy and prevent self-trauma by putting an Elizabethan collar on your pet. Spay or neuter your dog and do not allow exposure to unknown dogs.