How Old is Your dog in Dog Years?

It’s a dog life: Why the rule there are seven dog years in each calendar year is a myth. Smaller breeds tend to live longer than larger breeds However large dogs take longer to reach their full size So a small dog is older than a big dog at the age of two, but younger at five

By DANIEL MILLER

The old conviction that you can work out a dog’s human age simply by multiplying their years by seven is a clear case of barking up the wrong tree, claim researchers who say the real calculation is far more complex. As a general rule, smaller breeds live longer than larger breeds so a Yorkshire Terrier for example will, over the full course of its life, age much slower than say an Alsatian. However large dogs can take two years  to get to reach their full size but after that they may only live for another four or five years.

Little and large: As a general rule, smaller breeds live longer than larger breeds so a Miniature Dachshund for example will, over the full course of its life, age slower than a Great Dane. So while a small dog is effectively older than a big dog at the age of two, by the time it reaches five, it is actually younger.

The old conviction that you can work out a dog’s human age simply by multiplying their years by seven is a clear case of barking up the wrong tree, claim researchers who say the real calculation is far more complex. As a general  rule, smaller breeds live longer than larger breeds so a Yorkshire Terrier for example will, over the full course of its life, age much slower than say an Alsatian. However large dogs can take two years to get to reach their full size but after that they may only live for another four or five years. Little and large: As a general rule, smaller breeds live longer than larger breeds so a Miniature Dachshund for example will, over the full course of its life, age slower than a Great Dane. So while a small dog is effectively older than a big dog at the age of two, by the time it reaches five, it is actually younger. Dr Kate Creevy, assistant professor of internal medicine at the University of Georgia, told the BBC: ‘Small dogs reach skeletal and reproductive maturity sooner than larger breeds. Once they’ve achieved those measures of adulthood, they carry on to live longer. ‘It doesn’t happen in any other animal. There isn’t any other species which has within a single species the same degree of size diversity that dogs have. ‘It’s possible that by creating all of these diversely sized dogs that we unmasked this aging phenomenon.’

But size is not the only factor as by the age of three breed plays an increasingly important part. A bulldog, a medium sized dog, has the lowest average life span of just six years compared to a miniature poodle’s estimated to be between 12 and 15. Some experts believe cancer is partly responsible as it is far more prevalent in larger dogs than it is in the smaller breeds.

Short lived: A bulldog, a medium sized breed, has the lowest average life span of just six years. So working out your dog’s human age is a complex equation of age, size and breed that differs at different stages of the animal’s life. For the first three years, the figure can be gauged by size. For small dogs: 12.5 years per human year for the first two years For medium sized dogs: 10.5 years per human year for the first two years For large dogs: 9 years per human year for the first two years. Then for dog older than three years the type of breed comes into play. So you would multiply the figure by 13.42 for Bulldog, 7.84 for a larger German Shepherd and 4.32 for a Miniature Dachshund.

Dr Creevy added: ‘There is a long tradition of research into the cost of reproduction, and what has been shown across species is if you reproduce, you don’t live as long. ‘The question that raises is why would you die younger if you have offspring?’