Jack Russell terriers have the longest life expectancy, living for almost 13 years on average. Photo / Duncan Brown
A dog may well be for life, not just for Christmas, but how long that life is depends very much on the breed, according to a new study.
Jack Russell terriers have the longest life expectancy, living for almost 13 years on average, which is almost three times as long as some of the ultra-trendy, flat-faced dogs favoured by social media fashionistas.
French bulldogs, a brachycephalic breed known to suffer from various health issues because of the abnormally short snout and intense breeding, live the shortest life, with an average life expectancy at birth of just 4-and-a-half years.
The Royal Veterinary College (RVC) analysed data from more than 30,000 dogs in Britain that died between 2016 and mid-2020, and calculated the average life expectancy at birth.
Done in collaboration with the National Taiwan University, the researchers found that Yorkshire terriers were the second longest-living breed (12.5 years) and border collies were third (12.1 years).
Other flat-faced breeds – English bulldogs, pugs and American bulldogs – rounded out the bottom four alongside French bulldogs, with none of them expected to live more than eight years at the time of birth.
The study found that across all breeds, the average life expectancy was 11 years and three months. However, males tend to live four months less than females.
Female dogs tend to live longer than females for various reasons, said Dr Dan O'Neill, an associate professor in companion animal epidemiology at the RVC and a co-author on the paper.
"Possible explanations include differing levels of neutering as females may be more likely to be neutered than males," he told the Telegraph.
He added that males are more likely to be put down due to "undesirable behaviour" and also tend to engage in "higher levels of risk-taking" than females "with consequently higher risk of death from trauma".
Neutered dogs also lived longer than intact pets, with it being about a month longer for neutered males and about six months for spayed females.
The study included data from more than 250 different dog breeds as well as mutts, but there was only enough data for a league table to be created for 18 breeds as well as crossbreeds, which covered roughly half of all the canine study participants.
Labradors were the most common dog in the study, followed by Jack Russells and cocker spaniels.
Whilst the average life expectancy for all dogs was 11.23 years at birth, the equation changed after every year lived.
For example, by the time a dog is 4, it likely has less than eight years left to live. But at 10 years old this drops to 3.3 years, before falling to less than one year if a pet is 16.
The researchers also calculated at what point a dog can be expected to only have 18 months left to live and if an English bulldog makes it to 9, then it can be expected to see only one, maybe two, Christmases.
Jack Russell – 12.72 years
Yorkshire terrier – 12.54 years
Border collie – 12.1 years
Springer spaniel – 11.92 years
Crossbred – 11.82 years
Labrador – 11.77 years
Staffordshire bull terrier – 11.33 years
Cocker spaniel – 11.31 years
Shih-tzu – 11.05 years
Cavalier King Charles spaniel – 10.45 years
German shepherd – 10.16 years
Boxer – 10.04 years
Beagle (pictured) – 9.85 years
Husky – 9.53 years
Chihuahua – 7.91 years
American bulldog – 7.79 years
Pug – 7.65 years
English bulldog - 7.39 years
French bulldog - 4.53 years
In contrast, longer-lived dogs such as Yorkshire terriers, Jack Russells and mutts don't reach the 1.5-year end-of-life threshold until the pet is 14.
Dr Kendy Tzu-yun Teng, the lead author of the study from the National Taiwan University, said: "The dog life tables offer new insights and ways of looking at the life expectancy in pet dogs. They are also strong evidence of compromised health and welfare in short, flat-faced breeds, such as French bulldog and bulldog."
O'Neill added: "The short life expectancies for flat-faced breeds such as French bulldogs, shown by the VetCompass Life tables, supports the UK Brachycephalic Working Group's call for all owners to 'Stop and think before buying a flat-faced dog'."
Don't judge a dog by its breed
The study is published in the journal Scientific Reports, and came as a separate piece of research from the US found that dog breed is not as good a predictor of behaviour as previously believed.
Analysis of the genes of more than 2000 dogs, combined with surveys from their owners, found that there was no genetic link between breed and aggression, for example, despite common stereotypes.
They found that, on average, just 9 per cent of behaviour is explained by breed, indicating there is much more individualism than previously thought when it comes to dogs.
Researchers did not measure aggression directly as it is hard to define scientifically, but did look at "agonistic threshold", which stated how easily a dog reacts to a stimulus and shows displeasure. This can be anything from giving a side-eye, raising its hackles or growling, the experts said.
Dr Kathryn Lord, the study's co-author from UMass Medical School, said: "We found [agonistic threshold] was really not a very heritable factor at all."
Dr Elinor Karlsson, a biologist from UMass Medical School, added: "We can say that when we looked at this factor that we called agonistic threshold, which included a lot of questions about whether people's dogs reacted aggressively to things, we weren't seeing an effect of breed ancestry on that particular factor."