Tell me more about TVT

5th Dec, 2017

At work, we have been feeding a local stray dog for the past few months. We’ve called her Mischief and everyone is really fond of her. We’ve raised money to get her spayed and took her to the vet for a check-up.

To our shock we were told Mischief has TVT. I had never heard of this before. It sounds nasty! Please tell me more about the condition and how it will affect Mischief.

Lelanie Milner – Walkerville, JHB

Dr Mirjam van der Wel, Principal Veterinarian Animal Anti-Cruelty League, Port Elizabeth, answers…

TVT is short for Transmissible Venereal Tumour. It is a tumour that is transmitted (spread) through sexual contact (mating) of dogs. Much like a sexually transmitted disease in humans, except in this case the “disease” that is transmitted is a tumour. It can also be spread when dogs sniff and lick at the tumours. Genetically, the tumour is not actually part of your dog. It’s more like a parasite that catches a ride.

What makes this tumour so “special” is that it is one of the very few tumours known in animals that is transmitted through contact. Humans do not have tumours like this and the dog tumour is not contagious to people.

The tumours mostly present like fleshy growths on the genitals of male and female dogs. The owner of the affected animal will usually notice blood spotting from the dog’s penis or the female losing spots of blood as though she is in season.

In some cases, if left untreated, the tumours can become very big and debilitating. And, in rarer cases, (especially if the dog has not got a strong immunity) the tumour can spread internally.

Can this tumour be treated? How will the treatment affect Mischief?

Treatment consists of getting rid of the tumour and also spaying or castrating the dog so that future reinfection is unlikely as neutered dogs will not engage in mating.

The most commonly used drug in treatment of TVT is vincristine. This drug sometimes gets used in the treatment protocols of certain cancers in both animals and humans. Although vincristine is a very strong drug, which should only be used by a qualified veterinarian under strict conditions, the side effects we see in dogs are generally very manageable. The success of the treatment (and the side effects) can be directly related to the health of the animal. Good immune system = less problems.

Treatment varies per case but generally consists of three to six injections of vincristine with a week or two intervals in between injections. Your dog does not need to be hospitalised during the course of the treatment. If Mischief is an otherwise healthy dog the chances of successful treatment are very good.

Is TVT a typical South African dog disease or is it a bigger problem?

TVT has been seen all over the world. In fact, research has shown that this tumour has been around for many thousands of years. But because the tumour is primarily transferred through mating, the affected dogs are generally ones that roam the streets and practise “unsafe sex”. 

Veterinarians working in welfare situations here in South Africa will frequently see this condition, whereas those working in private practice, dealing with patients that live on enclosed properties, will rarely see TVT.

How can I prevent my dog from catching TVT?

If your dog is kept on an enclosed property and doesn’t hang out with “strangers”, he/she will not catch TVT. If, on top of that, the dog is spayed/neutered and will not engage in mating even if a stranger gets into your yard, the risk of contracting TVT is virtually negligible.

I wish you all the best with Mischief’s treatment and thank you for saving her from a life on the streets!

For readers with a further interest in TVT, have a look at