Can transmissible venereal tumor spread to other animals or humans?

This tumor spreads primarily between dogs through direct contact or mating; transmission to humans is extremely rare. If you are concerned about contagion, keep the affected animal separated from others and consult your vet for specific precautions.

What tests are usually needed to confirm the nature of the tumor?

Common tests include fine-needle aspirate cytology and tissue biopsy. X-rays or ultrasound may be added to check for metastasis when needed. A pathology report provides the definitive diagnosis — follow your vet's recommendations on which tests are required.

What is the prognosis for this tumor, and can it recur?

Prognosis depends on the extent of the tumor and the treatment approach. Most cases can be controlled or put into remission with appropriate care, though recurrence is possible. Regular follow-up as advised by your vet is strongly recommended.

How much do the tests and treatment usually cost?

Costs vary by clinic and region — ask your vet for an estimate before proceeding.

Disease Guide

Transmissible Venereal Tumor (TVT) in Dogs: Symptoms, Diagnosis & Treatment [2025]

A tumor spread between dogs during mating, typically cauliflower-shaped, and usually responds well to chemotherapy

Take 1 minute to check the symptoms first

Last updated: 2026/01/06

Pethealthmap Editorial Team

Sources: AVMA, WSAVA, National Taiwan University Veterinary Hospital

When to See a Vet

Seek Emergency Care Immediately

•Heavy bleeding from the genital area lasting several hours
•Rapid tumor growth or frequent rupture with bleeding
•Lethargy, inability to eat or drink normally

Schedule a Clinic Visit Soon (within 24–72 hours)

•Abnormal mass or persistent swelling around the genitals
•Recurring bloody discharge or blood in urine
•Loss of appetite for more than two days or unexplained weight loss

01What Symptoms Indicate a Problem?

This type of tumor typically appears on the genitals or perineum. In the early stages it may present as only a local lump with mild discomfort, accompanied by changes in energy and appetite.

A visible or palpable lump that may ulcerate or bleed at the surface
Abnormal or bloody discharge from the genital or perineal area
Reduced energy, dull response, or unusually quiet behaviour
Decreased appetite or changes in the amount and timing of meals
Lower activity level, reluctance to play or go for walks
Noticeable weight loss or significant fluctuation in body condition over a short period

Seek emergency care immediately if you notice the following symptoms:

⚠️ Seek prompt veterinary attention if the lump becomes infected or bleeding does not stop
⚠️ Go to an emergency clinic immediately if your pet develops rapid breathing or severe weakness

02How to Assess Abnormalities at Home: Key Observations and When to Seek Emergency Care

Observing and recording key information at home helps your vet quickly understand the progression and make the best treatment decisions.

Record your pet's energy level and willingness to interact or move around each day
Note the amount eaten at each meal and any refusals, including the time and quantity
Observe and document the nature of any genital discharge and whether bleeding is present
Weigh your pet daily or weekly and keep a record of any changes
Track daily water intake and the frequency and appearance of urination and defecation
If abnormalities persist or worsen, bring your records to the clinic for the vet to review

03How Will the Vet Diagnose This? Common Diagnostic Tests

The vet will start with a physical examination and basic tests, then proceed to cytology or imaging when needed to clarify the nature and stage of the tumor.

Physical examination

assessment of the lump's location, size, and possible invasion of surrounding tissue

Urinalysis

to rule out urinary tract infection or concurrent kidney issues

Cytology (fine-needle aspirate)

rapid cell collection for a preliminary assessment

Histopathology (biopsy)

to confirm tumor type and obtain a pathology report

X-ray or abdominal ultrasound

to evaluate for local or distant metastasis

Advanced imaging such as CT

for precise localisation, surgical planning, or complex case evaluation

04How Is It Treated and Managed? Medications, Diet, and Home Care Guide

The treatment plan is determined by the vet based on diagnostic results; regular follow-up visits with imaging or laboratory tests are required after treatment to monitor progress.

Treatment may involve local procedures or systemic therapy — your vet will explain the available options
Medication or other therapies are tailored to the diagnostic findings and your pet's individual condition
Schedule regular check-ups with imaging or blood tests as recommended to track the response to treatment
Dietary and nutritional support helps maintain body weight and overall immunity
Home care involves monitoring wound healing, any changes to the lump, and daily behaviour
Contact your veterinary team promptly if the condition changes or side effects develop

05What to Prepare Before the Vet Visit: Key Information to Help Your Vet Diagnose Quickly

Note when the symptoms first appeared and how they have changed over time

Bring a log of daily food intake, water consumption, and elimination patterns

Compile a list of all current medications, supplements, and vaccination records

Bring any previous test reports, X-rays, or ultrasound images if available

Film the lump or any abnormal behaviour on your phone — footage helps the vet assess the situation

If a referral is needed, take all records and images to the specialist hospital to facilitate further evaluation

This content is for reference only and cannot replace a professional veterinary diagnosis. If your pet shows signs of illness, please seek veterinary care promptly.