Small dogs with long snouts are most likely to live a long time. Dogs with flat noses and large dogs are, at the heart of the matter, likely to die.
Of the more than 150 breeds studied, the longest-lived dog is the Lancashire Heeler, a small terrier that has a life expectancy of 15.4 years. The Australian Shepherd, which lives on average 13.7 years, or the Jack Russell, which dies on average at 13 years old.