When choosing a healthy cat, it is important to consider the breed. Generally, purebred cats are more likely to have genetic health issues than mixed breeds. Some of the healthiest cat breeds include the Ragdoll, British Shorthair, Maine Coon, and Bengal. These cats tend to have fewer genetic health issues and live longer than other breeds. It is also important to consider the individual cat's diet, exercise, and lifestyle when assessing its overall health.