The idea that there are seven “dog years” in each calendar year is a myth because the animals age differently depending on their breed and stage of life, according to scientists.
Rather than simply multiplying their dog’s age in “human years” by seven, owners could come up with a much more accurate measure of its age by taking its size and maturity into account.
Smaller breeds live longer in general than larger breeds, meaning an adult chihuahua will age less every calendar year than a great dane, for example.
But the equation is complicated further by the fact that smaller dogs also mature more quickly than larger ones, meaning that in the early stages of life they age faster, experts said.
This means that after two calendar years, a smaller dog is “older” than a larger one – but after five years it becomes “younger” in relation to its total lifespan.
Dr Kate Creevy, assistant professor of internal medicine at the University of Georgia, said that once the varying rates of ageing at different stages of a dog’s life and its overall life expectancy are taken into account, the animals on average age about six, not seven years for every human year.
But this varies greatly by species. Bulldogs, which have a life expectancy of just six, will age about 13 years per calendar year while for longer-lived Miniature Dachshunds the figure is just four.
