He has good days where he runs around and bad days where he just goes outside to potty and goes back to bed. He had surgery 1.5 yrs ago to clear out a bladder full of large stones. He has stones again, and a UTI (we're treating it). He's on Benazepril. He had a dental about 6 months ago and did very poorly under anesthesia, to the point of requiring epi after his heart stopped. Now he has a tumor in his anal gland that is starting to grow rapidly. At this point it doesn't affect his function, it's just annoying and is causing recurring impaction/infection. He also has two teeth that need to be removed.
Sorry to be blunt but you asked...
Quality of life. Would you want to live with an anal tumor causing impaction? I wouldn't! It is your responsibility to make the hard decisions. Do for him what you would want someone to do for you.