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Average life span -

On average, dogs live for 10-13 years, which is considered roughly equivalent to between 60-74 human years.

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What influences canine longevity? -

But did you know that snout length, along with body size and sex, can influence how long a dog is likely to live?

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The Dogs Trust -

A study conducted by scientists at the Dogs Trust, the United Kingdom's largest dog charity, has shed light on the effects that parental lineage (pure vs. crossbred dogs), breed, body size, face shape, sex, and evolution have on the life span of companion dogs.

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Wide-ranging study -

The study authors examined data on 155 breeds plus mixes drawn from 18 different charities and organizations, incorporating over half a million dogs in the UK.

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Purebred breeds -

On average, companion dogs, breeds such as the Labrador or Border Collie, live for 12.5 years. Across all purebred dogs, median life expectancy was 12.7 years.

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Caucasian Shepherd Dog -

Key findings indicated, however, that flat-faced, or brachycephalic, dogs fared worse by that measure, breeds that include the Caucasian Shepherd Dog, which has a life expectancy of just 5.4 years.

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Presa Canario -

Another breed with a short life span is the Presa Canario. These dogs live on average 7.7 years.

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Cane Corso -

Similarly, the Cane Corso has a life expectancy of only 8.1 years.

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French Bulldog -

The French Bulldog lives a little longer, up to 9.8 years.

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Lancashire Heeler -

At the other end of the scale, the Lancashire Heeler enjoys one of the longest life spans, with an average life expectancy of 15.4 years.

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Tibetan Spaniel -

The Tibetan Spaniel is another dog breed known for its longevity. These canines live an average 15.2 years.

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Miniature Dachshund -

And the Miniature Dachshund belies its diminutive size by living on average 14 years.

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So, what's the difference? -

So, why do some dogs live longer than others? The study revealed some interesting conclusions.

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Body size -

Body size plays a role in longevity. Small and medium-sized breeds were found to live longer, with life spans of 12.7 and 12.5 years, respectively. Pictured is the Shiba Inu dog breed. These dogs live on average 14.6 years.

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Heavy-set breeds -

Heavy, large-sized breeds were found to have a 20% increased risk of shortened life span (in comparison to small-sized breeds) at 11.9 years. The beefy English Bulldog, for example, has an average life span of just 9.3 years.

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Face value -

The shape of a dog's face (i.e. ratio between the width and length of skull) also influences life span.

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Flat faces -

Brachycephalic dogs, those with flat faces, like the Pug (11.6 years), were found to have a 40% increased risk of living shorter lives than dogs with typical shaped faces.

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Typically living longer -

Dogs with typical shaped faces are exemplified by the Border Collie, who lives on average 13.1 years, and the aforementioned Labrador.

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Females live longer -

Female dogs (12.7 years) were found to live longer than male dogs (12.4 years), the study noted.

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Interaction -

Further analysis revealed that body size, face shape, and sex were found to interact.

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Long or flat characteristics? -

For example, a medium sized, flat-faced male is nearly three times more likely to live a shorter life than a small sized, long-faced female.

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Bucking the trend -

The study produced one surprising find. The near flat-faced Lhasa Apsos bucked the trend with one of the highest median life expectancies, at 14 years.

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Mapping the dog tree of life -

By commissioning the study, the Dogs Trust was able to map life expectancy across the dog tree of life, providing evidence that ancestral lineage is associated with breed life span.

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Related breeds, lower life expectations -

For example, clusters of related breeds with lower life expectancies included Caucasian Shepherd Dogs, Mastiffs, Bulldogs, Presa Canarios, Neapolitan Mastiffs (pictured), and Cane Corsos.

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Conclusions -

While the results of the study fell within expected patterns (for example, females lived longer than males, and small dogs longer than large ones), the paper fills a significant gap in research regarding canine life expectancy, according to Kirsten McMillan, a data scientist at Dogs Trust and lead author of the study. But the results come with a warning.

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The trouble with brachycephalic dogs -

"This paper is showing people that at a population level, [flat-faced, or brachycephalic] dogs are not doing well," McMillan said.

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"Health and welfare crisis" -

In fact, reports CNN, 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.

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Warning -

"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, adding: "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."

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A global study -

While these findings are pertinent 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 Silvan Urfer, an expert in dog life span at the University of Washington, speaking to CNN.

Sources: (Dogs Trust) (CNN) (Scientific Reports) (The Conversation)

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