Last night at 3 AM or so he wanted to go out, and he wouldn't come in. He made some awful howling noises, and walked right past me a couple of times. Eventually he came in and got on the bed, but for the first time since he's been sick, he seemed to be really suffering. I tried to comfort him, and found that his pulse was racing, well over 200.
When I woke up this morning, he was dead.
For my friends worried about me: I'm OK. I feel sad, but not devastated. I think it's easier to handle a natural death than euthanasia, and I've known for weeks that he was not just sick but definitely dying, so I was as ready for it as I could be.