Is Dog Cancer Contagious?

Have you ever wondered if you could catch cancer from your dog or if your dog could spread their cancer to other dogs? 

If so, you're not alone! I'm asked this question frequently at my oncology practice, and it's a common question asked of Google as well. 

The good news is that cancer in dogs does not spread to people. So you can rest assured that you and your loved ones cannot catch cancer from your dog (nor from other dogs). 

The interesting thing is that there is one type of cancer, typically seen in tropical and sub-tropical climates such as in the Southern US, Central and South America, China, the Far East and Middle East, and parts of Africa, that is transmitted from dog to dog.

Transmissible Venereal Tumor (TVT) is transmitted from dog to dog by close physical contact and usually affects the genitals - so it's often sexually transmitted. It can also be transmitted by licking, biting or sniffing tumor-affected areas, so the nose and mouth can be affected as well. It affects free-roaming male dogs most commonly (this group is more likely to engage in the behavior that places them at risk for transmission).

TVT is occasionally seen in the United States. The affected patients are usually in Southern California or Texas (places with hotter climates) and there is often a history of a recent adoption from outside of the U.S. (where the disease is more prevalent).

It is suspected that TVT originated in inbred wolves or dogs 10,000 to 15,000 years ago and has since spread worldwide.

TVT is most common in younger dogs, 2-5 years of age. In some cases, the dog's immune system can fight TVT and induce remission. If this happens, it's usually within the first few months of the disease. A spontaneous remission is rare after 9 months.

The good news is that if a patient's immune system cannot successfully fight the cancer, this tumor typically responds very well to chemotherapy. Even the more stubborn cases are expected to have long-term control with chemotherapy treatment; it is also responsive to radiation therapy. We expect patients to live for years after treatment for TVT.

Thankfully, TVT is the only known cancer that is communicable (can spread from dog to dog). 

If your dog has a different type of cancer (not TVT), you don't have to worry that it might spread to another dog, nor do you have to limit their exposure to other healthy dogs.


Have questions about this article? Reach out!

Dr. Lori Cesario
Board Certified Veterinary Oncologist 

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