I used to always hear that 1 year equals about 7 dog years. It was a belief I held through most of my childhood and would even do the math when I would get bored just to see how ‘old’ my dog was, marking each milestone as they came; at three, they’d be 21, making them legal to drink, at 5 they’d be 35, making them an ‘old dog’ in my eyes. When my dog turned 12, she was an old lady in both human years and dog years, and I’d exclaim she was my ‘oldest’ family member. Unfortunately, it isn’t that easy and scientists have found that this belief, while humorous, isn’t entirely true. 

So why is it that most people seem to pass along that 7 year myth? It was actually based on the fact that statistically dogs live until they are about 10 years old and humans live to about 70, so you would simply average those numbers, but scientists have found that it is a lot more complex than that. 

A dog’s ‘human’ age is broken down based on their weight and their average lifespan based on that weight. The American Veterinary Medical Association (AVMA) and American Kennel Club (AKC) found that the first year of a dog’s life is equal to about 15 human years for small and medium sized dogs and about 12 human years for larger dogs. The second year is then about 9 human years and every year past that is equal to about 5 human years. By the time the dog turns six, they are considered a senior dog. 

The age differs based on their breed and their weight. The AKC compiled a chart made up of four different weight classes. The first is small dogs, they weigh 20lbs or less and consist of dogs like dachshunds and pomeranians. Next is medium sized dogs, weighing between 21lbs to 50lbs, which includes dogs like corgis and border collies. After that they list large dogs, weighing between 51lbs and100lbs, which includes dogs like huskies and German shepherds. Finally there are giant dogs, weighing 100lbs and up, which includes dogs like English mastiffs and great danes. Giant dogs tend to have shorter lifespans and their age differs the most in the chart. They tend to reach ‘senior’ age by the time they turn 5 and age more rapidly than smallerbreeds. 

There is obviously room for error in this process as it can’t account for every variable, which can lead these estimations to being a bit off. It does, however, provide a good guideline to understand your dog's age and what that means for their health. Smaller dogs tend to live about 10-15 years (56-76 human years), medium sized dogs live about 10-13 years (60-74 human years), and larger dogs live about 8-12 years (55-99 human years). 

These estimations aren’t always accurate though and can be changed due to their dogs’ health conditions, environment, nutrition, or other extenuating circumstances and it can’t account for every single dog and their life. There are also outliers, like the newest world record holder for oldest living dog: Pebbles the fox terrier who is currently 22 yearsold! She just recently stole the title from TobyKeith, a 21 year old chihuahua, who had only just won the record in March! Both of these dogs surpassed the life expectancy for their size and are currently 110 years old and 105 years old respectively! There are several steps you can take to ensure your dog lives a long, healthy life:

• Feed them a nutritious diet
• Make sure they are a good weight
• Keep up with their veterinary trips and vaccinations
• Take care of their dental hygiene
• Take preventative measures to keep them safe from accidents
• Provide proper care to prevent against ticks, worms, and fleas
• And of course: love them and provide all of the love and affection they could ever need!

There is no way to predict what will happen in a dog’s life and a dog’s ‘human’ age could mean nothing in the long run, your dog could even be the next record holder after Pebbles. These are simply estimations that provide good guidelines that help to determine a dog's age and lifespan and a fun way to find out if your pup is older than you, even though, in our eyes, they’ll always be our little babies!

Photo by Anna Tarazevich

Written by Dani Forte