by Dogs mature much faster than humans, meaning these furry companions often don’t live as long as their owners. But how long do dogs typically live?
According to an April 2022 study in the journal, a dog’s lifespan can vary greatly depending on its breed Scientific Reports (opens in new tab). By analyzing the age of more than 30,000 dogs who died between 2016 and 2020, scientists calculated the average life expectancy of 18 breeds and crossbreeds in the UK.
The dogs had an average overall life expectancy of 11.2 years. However, the lifespans of these canine companions varied by breed.
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The creation of breeds some 150 years ago allowed dog breeders “to let our whims and desires run free as to how wildly and extreme we could reshape the dog’s body,” said the study’s senior author dr Dan O’Neill (opens in new tab), a veterinarian and epidemiologist at the Royal Veterinary College in Hertfordshire, England, told Live Science in an email. Given that many of these dogs no longer performed a work function, such as herding, retrieving, or guarding, “the requirement for good health was no longer an impediment” to creating new breeds, he noted.
The researchers found that small dogs lived longer than larger dogs.
“The lifespan advantage for small dogs actually contradicts the basic rules of lifespan for all species in the natural world, where smaller species generally live shorter lives than larger species,” O’Neill said. “A mouse might have an expectancy of one to two years, while an elephant might live to be 60 to 70 years.” (Some other research suggests that this general size-dependent longevity trend observed in all species may not always occur within a species applies; for example during a 2019 study (opens in new tab) suggested that taller females live longer than shorter females, this may not be true for males.)
One possible explanation is not that small dogs live longer, but that the larger breeds live shorter lives. Breeding may have resulted in large breeds that grow very quickly compared to their predecessors, inducing early onset diseases such as osteoarthritis and arthritis Cancersaid O’Neill.
Additionally, the death of 90% of dogs in the UK is linked to euthanasia, so their lifespans are “strongly influenced by human choices,” O’Neill said. Larger dog breeds with mobility issues may be more difficult to care for than smaller ones, or the financial cost of medical treatments may be greater for larger dogs than smaller ones as they age, he noted.
The scientists also found that the life expectancy of crossbred dogs was 11.8 years, about 6 months longer than the average for the entire group. This aligns with previous research that suggests hybrids are often healthier than purebreds, O’Neill said. Female dogs also generally lived longer than male canines, although this varied by breed, he noted. Neutering has also been generally associated with longer lifespans, possibly because it is often associated with greater owner responsibility and better care, and perhaps because it can reduce or eliminate a number of health problems related to reproductive organs and hormones, such as tumors.
All in all, the scientists found that Jack Russell Terriers had the highest life expectancy at 12.7 years, while French bulldogs had the lowest at 4.5 years.
“Unfortunately, while many breeds have maintained a basic healthy body shape — the Labrador Retriever, for example — several other breeds have taken a path to extreme body shapes — the English bulldog, for example,” O’Neill said. Shortly after breeding created these major physical differences, “the serious health issues associated with these extreme physiques became apparent,” he said.
Jack Russell Terriers may live longer than other breeds because smaller dogs live longer, O’Neill said. Also, they weren’t bred to have an unusual body shape that might limit their overall health.
“These little dogs were bred to be hardy and benefited from not being tied to a predefined breed standard,” O’Neill said. “Essentially, these are the archetypal healthy little family companion dogs.”
Other long-lived dogs also have body shapes similar to closely related wild species such as wolves, coyotes and foxes, which evolutionary forces likely optimized for survival and health, O’Neill said. For example, the average life expectancy for Yorkshire Terriers was 12.5 years, for Border Collies 12.1 years and for Springer Spaniels 11.9 years.
In contrast, breeds similar to French bulldogs often have short lives alongside. The average life expectancy was 7.4 years for English Bulldogs, 7.7 years for Pugs and 7.8 years for American Bulldogs.
Previous research has found that these breeds are prone to a number of serious health conditions, often related to their physical traits such as their short muzzle or large head. These conditions include skin fold dermatitis, breathing problems, eye ulcers, cherry eye, difficult childbirth, slipping kneecaps, elbow joint disease, and heat stroke.
“Many of these disorders are life-limiting because they either lead directly to the early death of these dogs, or owners choose to euthanize them for animal welfare reasons,” O’Neill said.
Although a common way of estimating the lifespan of dogs is to “dog years” — that is, multiplying their ages by seven to get an idea of how old they might be in human terms — recent work by O’Neill and his colleagues suggests “that such a concept really doesn’t hold up anymore is useful,” he said. “Given the large differences in life expectancy between breeds, an alternative approach would be to develop a concept of canine years within each breed. That’s a lot more likely to be accurate.”
