Canine transmissible venereal tumour - CTVT

[Astronuc]

https://www.wired.com/story/how-a-6000-year-old-dog-cancer-spread-around-the-world/
How a 6,000-Year-Old Dog Cancer Spread Around the World
A massive collection of dog tumor samples is revealing the secrets of a contagious, parasite-like cancer that could help explain human cancers too.https://www.cam.ac.uk/stories/canine-cancer
The curious tale of the cancer ‘parasite’ that sailed the seas

A contagious canine cancer conquered the world by spreading between dogs during mating. Scientists believe it arose around 6,000 years ago in Asia and spread around the globe through maritime activities.

Canine transmissible venereal tumour’ is a cancer that spreads between dogs through the transfer of living cancer cells, primarily during mating. The disease usually manifests as genital tumours in both male and female domestic dogs. It first arose in an individual dog, but survived beyond the death of the original dog by spreading to new dogs. The cancer is now found in dog populations worldwide, and is the oldest and most prolific cancer lineage known in nature.

I've had dogs and cats, and while I've heard of various viruses (e.g., parvo, . . . ) and cancers, I've never heard of CTVT before until now.

The Wired article has a discussion of a cancer spread by clams and mussels of which I was not aware.

 

[BillTre]

There is also a similar cancer of Tasmanian Devils.
It grows on their faces and is spread by cell transfer when they bite each others faces (something Tasmanian devils do a lot of apparently).