Many thanks to those who sent condolences on Mudpuppy's death. He'd lived with me very nearly his whole life -- when I adopted him he was only 4 weeks old and didn't know how to eat solid food yet, though he figured that one out really fast and was a pretty good-sized cat his whole life (around 15 lbs). When he died he was 18 years old; if he'd been a human I would have been sending him off to college this month. Unless he'd joined a gang or become a rock star or a professional athlete, of course, in which case I'd be retiring so he could support me in my old age.
He was diagnosed with diabetes in January 1996, and from then until his death I gave him insulin shots twice a day, every day. Since the shots had to be 12 hours apart and timing was pretty critical, I had to get up early on weekends and holidays (though I often went back to bed, being very much Not A Morning Person), and if I went out with friends for a drink after work, I had to make sure I was home by 7:30 at the latest. "Gotta run! I need to go stick my cat with needles." The shots themselves didn't bother him a bit -- in fact, after the first few when he sensed that I was nervous, I don't think he even noticed them. With insulin and careful dietary management, diabetes is something pets can live with long-term -- Mudpup was a fabulous example of that. His quality of life was excellent; in the last couple of years he wasn't very active, and was bothered by arthritis in his hips/back legs, but he spent many happy hours napping in his bed or on the couch or sitting on my lap purring up a storm.
I am heartbroken to lose him, and I will miss him terribly. But I know that he had about as happy a life as a cat can ever hope for, and I'm glad I was able to give him that for so long. House pets have one job in life -- to love and be loved -- and that's a pretty lucky life to have.