"Denise" said in
rec.pets.dogs.health:

I don't want to be selfish..............when should I make
the final decision? How should I make it?

An old regular used to say: Select three things your dog has
always loved to do (that could be eating, walks, etc.). Once he
shows no interest or is incapable of doing two of them, it's
time to start considering that maybe he's already made the
decision for you.

Balance that off with other quality of life issues that are
specific to your relationship with your Rottie.

There's nothing more difficult than making the decision you've
been confronted with. Good luck, it's one many of us have
faced. Your best support is a veterinarian whom you trust.

How do I live with it?

You just do. Trite, but true.

--
--Matt. Rocky's a Dog.