Life expectancy and body size

Large studies of pet dogs agree on the main pattern: smaller dogs live longer, and the heaviest breeds live the shortest lives. A 2024 study of more than half a million UK dogs across 155 breeds found a median lifespan of 12.5 years, with large breeds at roughly a fifth higher risk of an early death than small breeds and flat-faced breeds at about 40 percent higher risk¹. An earlier study of over 100,000 dogs in England put median longevity at 12 years, with crossbreds outliving purebreds by just over a year². Across breeds, weight is the strongest predictor of life span, and large dogs die younger mainly because they age faster⁴⁵. Life tables built from UK veterinary records give a life expectancy at birth of about 11.2 years overall, with a range from the Jack Russell Terrier at the top to the French Bulldog at the bottom³.

Body weight, more than height, is what shortens life; the effect works mainly by speeding up the rate of ageing in big dogs rather than by any single disease⁴⁵. Keeping a dog lean matters at every size: overweight dogs of twelve breeds lived measurably shorter lives than dogs in ideal condition⁶.

A breed's range is only a starting point. The figures on each breed's notes in Oldie come from breed standards and, where a published study reports one, a peer-reviewed median. Your dog is an individual.

This is general information, not a diagnosis. Your vet knows your dog.

Sources

1. Longevity of companion dog breeds: those at risk from early death (McMillan KM et al.). Scientific Reports 14:531, 2024 (peer reviewed). Accessed 2026-09-22.
2. Longevity and mortality of owned dogs in England (O'Neill DG et al.). The Veterinary Journal 198(3):638-643, 2013 (peer reviewed). Accessed 2026-09-22.
3. Life tables of annual life expectancy and mortality for companion dogs in the United Kingdom (Teng KT et al.). Scientific Reports 12:6415, 2022 (peer reviewed). Accessed 2026-09-22.
4. Statistical analysis regarding the effects of height and weight on life span of the domestic dog (Greer KA, Canterberry SC, Murphy KE). Research in Veterinary Science 82(2):208-214, 2007 (peer reviewed). Accessed 2026-09-22.
5. The Size-Life Span Trade-Off Decomposed: Why Large Dogs Die Young (Kraus C, Pavard S, Promislow DEL). The American Naturalist 181(4):492-505, 2013 (peer reviewed). Accessed 2026-09-22.
6. Association between life span and body condition in neutered client-owned dogs (Salt C et al.). Journal of Veterinary Internal Medicine 33:89-99, 2019 (peer reviewed). Accessed 2026-09-22.