In this blog, we cover what your dog's age is in human years, but using science instead of the 1 human year = 7 dog year rule.
What is a dog's average lifespan?
The average lifespan of a dog is between 10 and 13 years, but this varies between breeds. As a general rule, the larger the dog the fewer years it lives. For example, a miniature poodle averages 14.2 years, but a french mastiff averages just 5.5 years. As an exception to the rule, Chihuahuas, the world's smallest dog, have an average of 7.1 years. This can be explained though because they do experience health issues like hypoglycemia, dental and heart problems.
How did the original seven dog years to every human year rule come about?
This rule was based upon roughly dividing a human's lifespan of 80 years, by a dog's lifespan of around 12 years. However, it turns out this isn't quite right.
What's the new formula?
According to New Scientist, dogs age more quickly than humans, and it takes them just a few years to reach our middle age equivalent. However, this rapid age doesn't continue, it tapers off so a dog's aging, compared to a human's, slows down over time.
Here's the formula:
human_age = 16 ln(dog_age) + 31
Confused? You can cheat and use the calculator on New Scientist's article!
How did science discover this?
The scientists looked at 104 Labradors of different ages, from puppies to 16 year old senior dogs. They compared chemical changes to genes which fluctuate throughout life, called methylomes, compared to humans over a lifetime. Matching these methylomes allowed the researchers to convert between the physiological age of dogs and humans.
This same method could be used for other animals too, as the scientists also looked at mice and found that a mouse aged 2.5 years is equivalent to a dog aged 9 years.
The next step would be to research how aging can vary between dog breeds.