Every dog has its day – but some clock up more years than others. Now research has revealed that when it comes to longevity, small, long-nosed breeds are top dog, while flat-faced ones are more at risk of an early death.
Once size, face shape and sex were taken into account researchers found that overall small, long-nosed female dogs tended to have the longest lifespans among pure breeds, notching up a median of 13.3 years.
However, breeds with flat-faces – a trait that has become fashionable in recent years – had a median lifespan of 11.2 years, and a 40% increased risk of shorter lives than dogs with medium-length snouts, such as spaniels.
“Whilst previous research had identified sex, face shape and body size as contributing factors in canine longevity, no one had investigated the interaction between the three or explored the potential link between evolutionary history and lifespan,” said Dr Kirsten McMillan, the first author of the research from the charity Dogs Trust.
Writing in the journal Scientific Reports, McMillan and colleagues report how they analysed data from 584,734 pure and crossbred dogs – 284,734 of which had died – gathered from 18 organisations, including rehoming and welfare organisations, breed registries and pet insurance companies.
Taking into account all breeds and crossbreeds, the team found the median canine lifespan was 12.5 years, with female dogs living slightly longer than males.
To delve deeper, the team looked at dogs from 155 pure breeds, finding larger dogs tended to have shorter lives than smaller dogs, while the length of a breed’s nose also mattered.
Indeed, while miniature dachshunds had a median lifespan of 14 years, the figure was 9.8 years for French bulldogs. Experts have long said that brachycephalic breeds are prone to a plethora of health problems, including breathing difficulties and skin problems.
However, it is the huge and hairy Caucasian shepherd that turns out to be the underdog, with a median lifespan of just 5.4 years.
The team also found the median lifespan for pure breeds was longer than for crossbreeds, at 12.7 years and 12 years respectively, a result that is at odds with the idea that crossbreeds might be healthier because they have greater genetic diversity.
However, they were unable to consider different types of crossbreeds, meaning data for dogs of unknown parentage was combined with data from “designer” mixes such as the labradoodle that may have far more inbreeding, potentially muddying the waters.
While the team did not have data on how the dogs died, they hope the study will spur others to unpick the risk factors behind the variations in lifespan. McMillan noted the differences were probably down to a complex mix of biological factors, such as body shape and genetics, as well as environmental factors including diet, exercise and training.
“In general, these results help potential owners, breeders, policymakers, funding bodies, and welfare organisations make informed decisions to improve the welfare of companion dogs,” she said.
“But more specifically, I think this provides an opportunity for us to improve the lives of our canine companions.
“We are identifying groups that desperately need attention, so we can zone in on these populations and work out what the problem is.”