World's Oldest Known Cancer Found in Dogs

CC BY 2.0. Hans Westbeek

Researchers have sequenced the oldest known cancer, a tumor found in dogs that may have originated 11,000 years ago. Known as canine transmissible venereal tumor, the cancer is particularly unusual because it can be spread from dog to dog during reproduction.

The researchers, working at the Wellcome Trust Sanger Institute near Cambridge, studied two dogs, one from Brazil and the other from Australia. The cancer causes genital tumors, and is believed to have survived first in an isolated population, but then spread around the world about 500 years ago.

The team was able to determine that the first dog to develop the cancer was a husky-like animal with short, straight fur. "We do not know why this particular individual gave rise to a transmissible cancer," lead researcher Dr Elizabeth Murchison told the BBC. "But it is fascinating to look back in time and reconstruct the identity of this ancient dog, whose genome is still alive today in the cells of the cancer that it spawned."

The findings were recently published in Science. Murchison also researches the only other known form of transmittable cancer, which affects Tasmanian devils and is spread through biting. You can watch her fascinating TED talk on this subject below: