Researchers, ahem, pawed over data on half a million dogs' lives to get the definitive result on which species live the longest. The answer? Whippets – or dogs that are shaped like them. The study found that small, long-nosed dogs have a median life expectancy of 13.3 years.
But where do other dogs fall on the scale? To find out, the study published in Scientific Reports investigated the data of over 580,000 individual dogs in the UK. These dogs were classified as one of 155 official pure breeds or as a crossbreed.
As well as breed, the researchers collected data on the dogs’ sex and date of birth – plus date of death if applicable. In fact, just under half (49 per cent) of the dogs had already died before the study began. This helped them determine the death rates.
Using official descriptions of species, the researchers assigned each of the dogs a size (small, medium, or large) and a head shape (short-nosed, medium-nosed, or long-nosed). However, the researchers did not have this information for crossbred dogs, so results concerning head shapes are restricted to purebred dogs.
With all of this data, they calculated the median life expectancies of different categories. For example, female dogs – according to the study – have a life expectancy of 12.7 years, compared to 12.4 years in males.
The highest life expectancies came for small, long-nosed dogs of both sexes – like whippets, miniature dachshunds, and Shetland sheepdogs – at 13.3 years.
Medium-sized, short-nosed dogs, on the other hand, had the lowest life expectancies – particularly if male (9.1 years, compared to 9.6 years for females). English Bulldogs fit into this category.
Over half of the purebred dogs in the study were one of the 12 most popular breeds, including Labradors, Jack Russell terriers, and Cavalier King Charles spaniels. The study found that Labradors had a high life expectancy of 13.1 years, Jack Russells the highest (at 13.3 years), and Cavalier King Charles spaniels a bit lower, at 11.8 years.
Surprisingly, the study found that pure breeds generally live longer (12.7 years) than crossbreeds (12.0 years).
“Our results don’t agree with previous findings,” paper author Dr Kirsten McMillan told BBC Science Focus. “However, as with everything else, this is a complex issue, and we urge future researchers not to distil dog breeding into just pure versus. cross in the future.”
The researchers say that the results could help to identify dogs at risk of early death. “My hope is that our results help owners better understand what they are taking on and the range of factors that influence health and longevity, especially when acquiring a dog,” said McMillan.
They also suggest that future work should investigate ‘designer breeds’ like Labradoodles and Cockapoos, as these dogs have different levels of genetic diversity in their DNA to both purebreds and mongrels.
About our expert
Dr Kirsten McMillan is the DataSEA (Science Engineering & Analytics) Manager at the Dogs Trust. Her research has been published in PLoS ONE, the Journal of Animal Ecology, and Frontiers in Veterinary Science.
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