IF you are one of the many pet owners who believe that one year in a dog’s life  is equivalent to seven years of human age, you got it wrong.

A recent study from the University of California School of Medicine in San Diego (UCSD) found a better way to calculate a dog’s age.

The study said the formula is based on the shifting patterns of methyl groups that occur in both dog and human genomes as a result of aging. This includes the number of chemical tags as well as where they are positioned.

A total of 105 Labrador Retrievers were subjected to targeted DNA sequencing by the research team in an effort to compare the epigenetic clocks of dogs and humans.

An epigenetic clock is a type of age-determining biochemical test. 

What is the formula?

In order to identify the age of a dog, researchers said pet owners could multiply the dog age’s natural logarithm by 16 and then add 31 or simply use the formula: (human_age = 16ln(dog_age) + 31).

A quite complex formula, right? 

But to put it simply, here’s the illustration made by the US-based animal registry American Kennel Club to illustrate a dog’s age depending on their age and their size:

Owners can also consider the following steps in calculating the dog’s age, according to American Kennel Club:

Step 1: A dog’s first year of life corresponds to 15 human years. 

Step 2: A dog’s second year of life is about equivalent to nine human years. 

Step 3: About four or five human years are added for every additional year.

The study revealed that smaller breed dogs live longer than large dogs since there are some pieces of evidence from the study that larger dogs may experience the onset of age-related disorders at an earlier age. 

There is also some evidence that the faster growth of large dogs may lead to an increased risk of aberrant cell growth and mortality from cancer, it said.

Why is this formula ‘more accurate’ than the 1:7 method?

According to researchers, dogs are bred differently, and it is important to consider their sizes in order to calculate their dog ages accurately.

“This makes sense when you think about it — after all, a nine-month-old dog can have puppies, so we already knew that the 1:7 ratio wasn’t an accurate measure of age,” UCSD School of Medicine professor Trey Ideker said.