Siamese cats are reputed to be one of the longest-lived purebred cats, although their average lifespan of 13 to 14 years is well within the overall cat average lifespan of 12 to 15 years. Very well-cared-for Siamese cats can live into their early 20s.
Siamese cats are considered one of the healthier breeds out there, but they still have their share of hereditary illnesses. In particular, the wedge-shaped head called for by the breed standard encourages respiratory illnesses and dental problems that can shorten the cat's life if not looked after carefully. Siamese can also suffer from heart problems, renal failure and cancer. Indoor cats of all breeds live longer than outdoor cats due to reduced exposure to communicable disease and fatal accidents.