Most small dog breeds are expected to live into the double digits, but there's no way to guarantee this. Small dogs in general have a longer lifespan than larger dogs, but many factors play into how long you can expect your dog to live. The overall health of a pet, coupled with the diseases that certain dog breeds are predisposed to, will affect life expectancy. Some small dogs live much longer than what is expected of their breed while others unfortunately don't, but in general, small dog breeds live longer than most large dog breeds. The following are life expectancy averages of specific small dog breeds, such as Bichon Frise - 12 years, Boston Terrier - 11 years, Cairn Terrier - 14 years, and Toy Poodle - 13 years. Small dogs often live longer than large dogs because large dogs age more quickly. Indoor dogs that are spayed or neutered are less likely to be hit by a car and be injured or die, so regardless of breed, lifestyle may also play a role in how long a dog lives. Factors such as the lifestyle a specific dog lives, the nutrition it receives, and preventative measures that its owner takes to limit infectious diseases and parasitic diseases can all play roles in how long a dog may live.