Two days ago my cat died very suddenly. It seems to me to have been more traumatic than any answers that I have found so far. We noticed him on the couch he was completely stretched out and he would twitch and then desperately suck in air. When I looked at him, his eyes were completely vacant and there was no response from him at all. The twitching got progressively worse until he finally died. He never made a sound through any of it. From the moment we noticed him and death was probably no more than 5 minutes but it wasn't the instantaneous death I keep reading about. He was 13 but very healthy. I had blood work done every year and never had anything show up. He was on special food cause he got bladder stones about six years ago but we never had any problems once he was put on the diet. He did not show any signs of distress throughout the day. In fact, he had been running around with our younger cat just a little bit earlier. Only issue we were having was coughing up hairballs every once in a while and about an hour before he died he ate his food too fast and threw it up. He has done this his whole life, the food comes back up whole cause he never chewed it. He always had food so I never did understand why he would scarf it down.
