I do get people wanting to keep a dog longer around, when my dog got cancer we knew it wouldn't last long.
could have operated but the vet said that would not help him much, thing is in the end its only a dog. Just give it the best few months it has left.
Hell I even gave mine chocolate in the end, not supposed to give it to a dog, but I was like oh well you don't have long to go eat as much as you want.