I posted then deleted my post. I think I was too wordy.
I have a 14 year old cocker. She has a heart arrhythmia and is mostly deaf and blind. Her teeth need cleaning, but I won't do it. For me, it's not worth the risk. She's probably got a couple years left in her, but I'm afraid the trauma (emotionally and physically) of the anesthesia just isn't worth it- for either of us.