I had a 6 year old cat that died this past Saturday. He was fine in the morning playing and acting himself. My husband works midnights and he came on to bed and I got up 20 minutes later and found my beloved pet dead in the middle of the living room. I called my vet right away but they would not take him for an autopsy. I wanted to know what happened to him. He was not sick, he was very playful and full of life. How could something happen so suddenly?
If your cat was healthy then suddenly died, it is possible that he threw a blood clot (thromboembolism). This is just a quess. There is not much you can do when this happens. sorry. vetcare