Bull, the dog in my avatar, had mesothelioma...human asbestos cancer. Go figure? At the time he was one of a handfull, and none survived it. That's why we went hunting for the month after his surgery, until I could see he wasn't interested in it anymore, then we went home for a "soft landing".
Thankfully I'd had him collected, and I have one of those 'miricle' pups. The young Tank has a lot of his daddy and his grandpa in him, for which I'm thankful.
Chief, another of Bull's pups, is now almost 9. He shows some signs of aging...mainly getting stoved up after a lengthy hunt, and a greying muzzle. But so far he recovers well with a couple of Bufferin, and has unending desire. He's a far better pheasant hunter than his daddy was.
I'm certainly not looking for any cancer to invade either of these dogs lives, but time will tell. And if it did, I'd not consider it as being hereditary.
Last spring my yellow (Backwater Rudy x Abe's Magic Maggie) escaped the fenced yard and while he was out a neighbor noticed a bloody stool he was diagnosed with colon cancer. He lost about 1/3 of his weight and became weak and had to be put down.
I don't believe it to be hereditary, but I think they are genetically predisposed to develop the disease.
We lost our "first" lab about two months ago to Cancer. Not sure
what type but it was fast spreading and in her lungs/chest. She
was 8 almost 9 years old. To me she was still to young to die.
I called the owner of her Mother to maybe find out if the Mother
might have had cancer (she would be about 13 or 14). They had
put the Mother dog down just last summer. No Cancer....
Our Lab was healthy and tough. Never would believe we would
have had to go through what we did with her. To long of a story
to write about but..... I have wondered what caused her to develop
the cancer she had. It took almost 3 months to know beyond
a shadow of doubt.... that she did indeed have cancer. It wasn't
anything in her "genes". I think it was just the Luck of the Draw".