How to Calculate How Old a Dog Is

Unless you know your dog's birthday, estimating its age can be difficult. But when you adopt a dog or take in a stray, knowing its approximate age is helpful for a variety of reasons, from knowing which food to choose to anticipating health problems. While there is no way to know the exact age of the dog, you can use a few general tips to estimate the age. Remember that many small dog breeds, like Chihuahuas, can live up to about 18 years while giant breeds, like Great Danes, have much shorter life spans, up to about 10 years. You can use that information when you estimate at what stage of life your dog is in.

Things You'll Need

  • Dog
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Instructions

    • 1

      Look at your dog's teeth to try to determine its age. Young dogs still have their puppy teeth, which are small and very sharp. If the dog is a puppy, it should not have much tartar buildup and the teeth should look clean, white and strong. A dog in middle age will likely have teeth that are darker white, yellowed or even brown. The tartar buildup will be visible at the gumline of the teeth. Senior citizen dogs will have light brown teeth and could even be missing some teeth. These markers are easier to read if the dog has not had regular dental care.

    • 2

      Check your dog's fur to help determine its age. Puppies and dogs in their middle years have shiny, thick fur. As dogs get older, their fur can become duller and thinner. Many dogs also become gray or white around their muzzles when they are in their later years.

    • 3

      Watch how your dog moves to help determine in which stage of life it is. Puppies and younger dogs play in a very boisterous manner and may run so hard they flip themselves over or even slam into walls without seeming to care. Dogs in their middle years typically still like to play, but they have better control over their feet and movement. Old dogs might start to experience joint pain, just like older people, so they might be less likely to play and might seem to move with more care.

    • 4

      Consider all of these factors when you are trying to determine how old your dog is. While one factor is not enough to figure out your dog's age, several can work together to give you a general idea of your dogs age, or its stage of life. A veterinarian can also help determine a dog's age.