How old is your dog?

Our new research has found our dogs are not necessarily in the age category we might think they are.   

We’ve all heard the old saying that dogs age seven years for every one human year, but a Dogs Trust researcher says things aren’t that simple. And the findings will enable all of us to better care for our four-legged friends.  

Dr Naomi Harvey, Research Manager at Dogs Trust and Honorary Associate Professor of Companion Animal Behaviour & Welfare at The University of Nottingham, has reviewed scientific literature on aging in dogs - the conclusions of which have been published today (Tuesday 27th April) in Frontiers in Veterinary Science.  

Dr Harvey said:  

“Dogs mature more quickly than we do. Many one-year-old dogs have reached their full height and most will have gone through puberty or be approaching the end of it, so they’re definitely not the equivalent of a seven-year-old child! 

“A quick internet search reveals that there are many dog age calculators available online. Most typically agree that a dog that has just turned one is equivalent to a human around the age of 15, although these age calculators generally adjust their calculations based on how long certain breeds are expected to live.  

“It’s common to read statements that say dog breeds age at different speeds, with some dog breeds aging much faster or slower than others. But I wanted to look at whether this is really true.” 

Dr Harvey searched through scientific publications on signs of behavioural aging and development in dogs aiming to work out at what age a dog can be considered a puppy, juvenile, adult, senior or geriatric.   

In her review, she concluded that there is evidence to suggest that a one-year-old dog is indeed still juvenile just coming out from puberty (so the comparison to a 15-year-old is about right) and that dogs don’t become mature adults until they’re two, which marks the end of adolescence (equivalent to when people are aged around 25). She found that dogs can be considered to be entering their senior years (when an animal is older but typically still quite healthy) at age seven, and that they can be classified as geriatric (a stage of aging where poor health or death becomes most likely), at age 12 and over.   

In the UK, the average lifespan of a pet dog is 12 years (across all breeds). Some dogs however reach ripe old ages of 15 and over, and dogs this age can be considered ‘very aged’.  

As some dog breeds live on average far shorter lives than others, it is common to adjust a dog’s age category by their breed life expectancy to decide when they are ‘senior’ or ‘geriatric’. Based upon evidence for how dogs age behaviourally, Dr Harvey argues that we shouldn’t be doing this: 

“Certain dog breeds are expected to have shorter lifespans, with some, such as the Great Dane (pictured), having an average life expectancy of just six years in the UK. In terms of their health, these dogs do decline quickly, meaning they need additional veterinary care when they’re much younger than other dogs. But whilst their bodies may be impacted by health problems when they’re still young, there’s no evidence that short lived breeds are aging in the true sense of the word, as behaviourally they appear to be following the same trajectory as other dogs. In other words, short lived dog breeds are not aging faster, they are simply dying younger. 

“The language we use to describe dogs and consider their age matters. By saying that these dogs are aging faster, and using language such as ‘geriatric’ to describe a dog that is objectively still young, and a dog that should be in the prime of its life, we’re masking the health and welfare issues associated with certain breeds of dog.” 

Read the full research paper.

To find out more about looking after or adopting an older dog please go to: Rehoming and looking after an older dog