For their size, cats live quite a long time. Generally an animal's longevity is proportional to its size (with the exception of tortoises, man and a few other animals). A tiny mouse has a short lifespan, a rabbit somewhat longer and a dog between 7 and 20 years depending on its breed or size, its activity, or both. Cats aren't much bigger than rabbits, but whereas the rabbit may live about 8 years a cat will live on average about 12–14 years, and it's not unusual for cats to reach their late teens or even their early 20s. In fact, "Creme Puff" From Texas lived to be 38.