I have an OLD dog that still might have a few retirement years left in him, he did his job so he desirves it, but he has a tumor on his backside that is spliting the skin and seem to be painfull to him. Any advise? I hate to put him down already and the vet wants way to much to remove it. This dog has tumors all over him but this one looks painfull. It's about 1"x1" and seems to be getting larger, that's why it's splitting the skin. Any adivse would be nice!