Scientists find key characteristic could determine how long your dog will live

Stock image of happy dog
The study looked at data from more than 584,000 dogs across the UK. Photo credit: Getty Images

Is your dog a small male with a long nose? Or a medium-size female with a face of average canine proportions? If so, your furry companion is more likely to be at your side for a long time, according to new research. But if yours is a pooch with a squished muzzle, the picture might be a bit less rosy.

A large study published Thursday looked at data from more than 584,000 dogs across the United Kingdom and found that snout length, along with body size and sex, can influence how long a dog is likely to live.

"A medium-sized, flat-faced male like a bulldog is three times more likely to live a shorter life than a small-sized, long-faced female, like a miniature dachshund or an Italian greyhound," said Kirsten McMillan, a data scientist at Dogs Trust, the UK's largest dog charity, and lead author of the paper in the journal Scientific Reports.

'These dogs are not doing well'

The study authors examined data on 155 breeds plus mixes. While a typical Labrador retriever or border collie had a median life expectancy of just over 13 years, the researchers found that almost across the board, flat-faced, or brachycephalic, dogs fared worse by that measure. That shorter-nosed bunch included large mastiffs (9 years), beefy English bulldogs (9.3 years) and French bulldogs (9.8 years).

"This paper is showing people that at a population level, these dogs are not doing well," McMillan said.

One smush-faced survivor stood out in the findings: Lhasa Apsos clocked in with one of the highest median life expectancies at 14 years. That's up there with Shiba Inus (14.6), papillons (14.5), miniature dachshunds and Italian greyhounds (14).

Most of the results fell within expected patterns. Females lived longer than males, small dogs longer than large ones. Small and medium dogs with pronounced schnozes lived over 12 years on average, while flat-faced dogs of all sizes fell short of that mark.

The grim outlook may or may not come as a shock to owners of Frenchies, America's most popular dog breed. (Last year, it unseated the Lab, which had held the title for three decades.) It's well known that the bat-eared darlings are predisposed to a number of health issues, often owing to their flattened face shape - breathing problems, skin infections and eye trouble to name a few. Pugs and English bulldogs face these challenges, too.

The Brachycephalic Working Group, a consortium of veterinary organizations, breeding associations and nonprofits in the UK, has declared "a health and welfare crisis" for flat-faced breeds.

"This new research underlines these major health issues by revealing that flat-faced dogs live 1.5 years shorter lives than typical dogs," said Dan O'Neill, an associate professor at the Royal Veterinary College in London and the working group's chair, in a statement. "We urge anyone considering getting a flat-faced breed to 'stop and think' and to ensure that they acquire a dog with the best chances of a long and happy life."

Esme Wheeler, a dog welfare expert at the Royal Society for the Prevention of Cruelty to Animals, concurred. "We completely understand why there is so much love out there for these breeds, but breeding bodily features which compromise the basic health and welfare of pets is wrong," she said. "Health and welfare should always be the priority, not fashions or aesthetic trends."

Neither O'Neill nor Wheeler contributed to the research.

Though limited to the UK, the results would probably be similar in the United States, especially with respect to pure breeds, since they are fairly standard around the globe, said veterinarian Dr Silvan Urfer, an expert in dog life span at the University of Washington, who was not involved in the research. However, he posited that there might be more differences between mixes there and in the US.

"It's an excellent study that makes a very good point regarding the breeding of short-nosed dogs," Urfer said. "I'm not at all surprised that brachycephalic breeds didn't live as long."

The designer dog debate

One of the study's more surprising takeaways was that purebred dogs were found to outlive mixes by about eight months. This finding doesn't align with the commonly held notion that mixes are generally heartier and healthier than their inbred kennel club counterparts. But the current study can't tell the whole picture, McMillan said.

The data - collected from vets, breed registries, rescue organizations and pet insurance companies - divided dogs into two categories: purebred and crossbred. Within the crossbred category, the data did not distinguish between genetically diverse mutts and intentional crosses, or "designer breeds," such as the cockapoo, labradoodle and cavachon.

These are not random mixes or the products of natural selection. "We're talking about strategically bred dogs and that has changed the game," McMillan said. Dogs Trust is already working on a new study to determine whether these popular crosses have longer or shorter life expectancies than the breeds they're derived from.

"Designer dogs is a relatively new phenomenon, so you have a population that skews young," Urfer said. Studying the population as it grows and ages should give better insight into the health and longevity of these burgeoning breeds.

The study includes millions of data points, but it doesn't necessarily represent the full spectrum of companion dog life, McMillan said. For instance, not everyone has pet insurance or makes regular vet visits.

The research also did not account for cause of death, which is often euthanasia.

"The ethical and welfare concerns surrounding dog breeding have become one of the most important issues - if not the most important issue - within canine welfare," McMillan said.

"I hope this paper is a catalyst to start policymakers, government, vets, owners, everyone asking, 'Why are these dogs dying?'

"It will be very difficult to answer, but every time we answer even a small part of it, we are progressing towards having a much healthier canine population."