You picked up your best friend from the Humane Society. Or maybe from a family member. Or maybe some other way. The point is, that little mixed-breed buddy has become a valued member of your family.

He might be big or he might be medium. Heck, he might be just a little guy, waiting there for you every day at the door. Man, is he glad you're home!

So just out of curiosity, how old is he anyway?

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Hmm, good question. We've all heard about the 'A dog ages 7 years for every human year'. And that's, well, kind of in the ballpark. But there's a better way to find out how old Fido is.

The pets section at WebMD actually has a chart that narrows down Rover's age. And in large part, it has to do with his...

...teeth.

You can check out the details here, but to give you an idea if he has all his baby teeth, he's about 8 weeks. If the permanent teeth have shown up nice and shiny, he's hit the 7-month mark. Take a peek...if there's some yellowing on those back teeth he's about 2 years old.

Oh, it's not exact by any means, but it'll give you an idea. And your Vet can narrow it down even more with an exam of the bones, joints, muscles, and more.

And best of all, you can go ahead and give him any birthday you want. After all, isn't any day and every day a good day to give your special friend a treat?

7 Famous Athletes from South Dakota

South Dakota may have a small population, but our state's contributions to sports have been pretty big.

People born in the 605 have gone on to be in the NFL, Major League Baseball, the NBA, WWE, WNBA, and in the Olympics.

Meet seven of the most famous: