Dog Cancer That Spreads Directly

Canine transmissible venereal tumor is a contagious cancer in dogs that spreads when cancer cells themselves are physically transferred during sexual copulation, not through bacteria or viruses. Infected dogs pass living tumor cells to each other, which then take root in the new host’s tissues and grow as a grafted cancer. It is one of only three known directly transmissible cancers in mammals.

Previous Fact Next Fact