Another cherished belief, originating in the 1950s, bites the dust: One dog year is the equivalent of seven human years.

From the American Kennel Club (akc.org): "Even though this formula has been around for a surprisingly long time, the reality is not so cut and dried. That doesn't stop people from defaulting to this traditional calculation.

'You really can't kill the seven-year rule,' says Kelly M. Cassidy, a curator of the Charles R. Connor Museum at Washington State University, who compiles studies about longevity in dogs."

Apparently the formula for the 7:1 ratio seems to have been based on the statistic that people at the time lived to about 70, and dogs to about 10.

"My guess is it was a marketing ploy," says William Fortney, a veterinarian at Kansas State University. He tells The Wall Street Journal that it was "a way to educate the public on how fast a dog ages compared to a human, predominantly from a health standpoint. It was a way to encourage owners to bring in their pets at least once a year."

Well, that paid off, didn't it? I might blow off my yearly wellness check (formerly known as a physical), but never miss my dogs' yearly exams, despite their ever-increasing cost.

Here's the new guideline, issued by the American Veterinary Medical Association:

Fifteen human years equals........

© El Dorado News Times