We’ve all heard that one year for a dog is equal to seven years of human life right? Well, that’s not quite accurate, as it doesn’t take into account the dog’s breed or size. Even though this “rule of seven’s” has been around since the 1950’s but science has determined it doesn’t hold water.
According to the American Veterinary Medical Association you can use these general guidelines to more accurately estimate your dog’s age in human terms:
For a medium sized dog, the first year of life equals about 15 human years.
The second year is roughly equivalent to nine human years.
After that, each human year equals five years for the dog.
Large dogs age faster than small dogs although scientists are still not exactly sure why this is so. This is the reason why a large dog like a Great Dane could be considered a “senior” animal at age seven, when a small dog, such as a Chihuahua, with a life expectancy of 12 to 20 years, would still have plenty of life left.
The American Kennel Club has more about dogs and their lifespans plus a table that allows you to calculate your dog’s age in human years depending on whether they are a small, medium or large breed.