It's happened in the wild a couple times: https://en.wikipedia.org/wiki/Canine_transmissible_venereal_tumor?wprov=sfla1 https://en.wikipedia.org/wiki/Canine_tr

It's happened in the wild a couple times: https://en.wikipedia.org/wiki/Canine_transmissible_venereal_tumor?wprov=sfla1 https://en.wikipedia.org/wiki/Canine_transmissible_venereal_...