Yes. Many references for this topic, Google "evidence of pathogenic cause cancer". This one looks like a good read: https://www.sciencedirect.com/science/article/pii/S295019462... "Role of infectious agents in cancer pathogenesis and therapy" for a dozen examples. There's so many more in reality.
It's not. It's just that their immunity is very tolerant to other members of their specie so having a cancer of the face in a specie that frequently bites each other in the face is transmissible. Afaik there is no pathogen involved.
The a smart way to look at it. But for full generality, I consider cancer particles emitted from tumors such as during surgery as pathogenic vectors of cancer whether an underlying cause involves microbial hosted or just the cancer cells themselves cancer definitely has a bit of a panspermia thing going on.
That’s why I never wanna spend time in cancer wards. It is most definitely contagious across multiple vectors in unique ways.
