Whooza good at math!

Calculating a dog’s ‘human age’ isn’t x7

Maybe you can’t teach an old dog new tricks — but scientists have found a new trick to determine the age of old dogs.

One of the most commonly held puppy tales — that you can calculate their “human age” by multiplying their years by seven — is being debunked by scientists at the University of California San Diego.

And it turns out your pooch might not be as senior as you think.

Here’s how it works: Rather than a simple equation, their new method — released ahead of peer review on bioRxiv — is based on how doggie DNA ages over time.

Geneticists Tina Wang and Trey Ideker of UCSD and their teams used a process called methylation to find the answer. As animals grow old, DNA becomes saddled with chains of atoms called methyl groups, which alter DNA activity. Scientists call this the epigenetic clock and have found the process to be a reliable measure of age.

Canine life spans vary widely by both size and breed, yet all pooches exhibit a similar developmental pattern. For that reason, researchers felt they could narrow their study to a single breed — the Labrador retriever — and still derive a more accurate method of age measurement.

They compared dog data from 104 Labradors, ages up to 16 years, to already published methylation profiles from 320 humans, ages 1 to 103, in addition to those of 133 mice. Researchers found that humans and pups age most similarly in their youth and realign in their elderly years.

“Comparison with human methylomes reveals a nonlinear relationship which translates dog to human years, aligns the timing of major physiological milestones between the two species, and extends to mice,” the study authors wrote in their report.

The alignment of epigenetic clocks helped scientists devise a formula: human age = 16 x ln (dog age) + 31. (The ‘ln’ is an abbreviation for the natural logarithm, which is an additional calculation.) For example, if a Labrador is 12 years old, the formula would be 16 x ln (12) + 31 = 71. So your 12-year-old dog is about 71 in human years.

Using the previous calculation, a 12year-old dog would have been 84 in human years.

Still, the epigenetic clock comparison showed that the formula works best for pups in their youth and their senior years; it didn’t ring true as much during the dogs’ middle years. Plus the formula won’t be as reliable for breeds that tend to have shorter life spans than Labs.

Still, the researchers say, this answer yields a much closer comparison than previous metrics.

Research on the subject is far from finished. Just last week, veterinary researchers launched the Dog Aging Project, which will analyze 10,000 puppy participants’ diets, physical activity, gut microbiome and more.