Small dogs live the longest, averaging 15 years or more. Chihuahuas and toy poodles often reach 18+ years.
Mid-size dogs average 10-13 years. Beagles, Australian shepherds, and corgis often fall in this range.
Big dogs have shorter lives, averaging 8-10 years. Great Danes live 6-8 years while Labs average 10-12 years.
Giant breeds have the shortest lives at 5-8 years. This includes mastiffs, Saint Bernards, and other huge breeds.
Mixes inherit size traits from their parents. Small mutts live longer than big crossbreeds.
Dogs with chronic conditions like diabetes may have shorter lifespans than healthy dogs.
Overweight dogs are more prone to joint issues, heart disease, and cancer that cut life short.