12/08/2024
Do size and breed really influence the lifespan of dogs?
Companion dogs are one of the most phenotypically diverse species, with around 350 different breeds. Variability between breeds extends not only to appearance and behaviour, but also to longevity. Despite this fact, there has been little research devoted to assessing the variation in life expectancy between breeds or evaluating the potential for phylogenetic characterisation of longevity.
A new UK study analysed an enormous dataset of 584,734 unique dogs, including 284,734 deceased. The researchers presented variation in longevity estimates within the following parameters - parental lineage (purebred vs crossbreed), body size (large, medium, small), s*x, and cephalic index (brachycephalic/flat faced, mesocephalic/medium length and width head, and dolichocephalic/elongated head).
The 12 most popular breeds accounted for half of all purebred dogs. Average lifespan of some popular purebreds includes Labrador Retrievers with a median life expectancy of 13.1 years, Border Collies also averaged 13.1 years, Border Terriers 14.2 years, Bulldogs and French Bull dogs 9.8 years, whilst Mastiffs averaged 9 years.
The researchers found that small dog breeds with elongated noses, such as Whippets, generally live the longest, whilst medium-sized breeds with flat faces, such as Bulldogs, have the shortest lifespans.
Overall median survival for small sized breeds was 12.5 years, medium breeds 12.7 years, and large breeds 11.9 years. Variation was evident between pure and crossbred dogs, with purebreds living longer averaging 12.7 years, whilst median survival for crossbreds was 12.0 years.
The study found evidence linking breed longevity to domestication and artificial selection, providing evidence to inform discussions about health amongst breeds, which is potentially helpful for owners, breeders, policy makers and welfare organisations.