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How Old Is My Dog?

Mychelle Blake
Woman Hugging German Shepherd Dog

If you've had your dog ever since it was a puppy, it's easy to tell how old your dog is by using his birthdate. But for the many people who adopt older dogs from a shelter, their dog's true age can be a real mystery.

Using Teeth to Age a Dog

The most common way to determine a dog's age is through his or her teeth. You can't tell a dog's exact age, but examining the teeth can give you an approximate idea of your dog's age range:

  • When a dog is a puppy, their deciduous teeth (baby teeth) are fully formed by about eight weeks of age.
  • Their permanent teeth come in by about five to six months of age. A dog in good health at age one year should have clean, healthy-looking teeth.
  • As the dog grows older, tartar will form as well as cracks, ridges, and wear from normal use.
  • A senior dog, even with good dental care, is likely to show a lot of wear on the teeth and tartar as well as possibly missing teeth and dental disease. An older dog may also have bad breath.

Keep in mind that how accurate this method is will vary depending on the shape of your dog's teeth. A dog that has had regular dental care and cleaning will obviously have better teeth than a dog that has had little veterinary care. As a result, two dogs of the same age with different levels of dental care during their lives may be aged somewhat differently because the quality of their teeth is not the same.

Other Ways to Age a Dog

Visually examining your dog can also provide clues to your dog's approximate age. These signs are useful for looking at dogs that clearly are not young puppies.

Cloudy Eyes

Many dogs will develop a "cloudy" appearance to their eyes as they get older. Senior dogs also often have eye conditions related to cataracts and vision loss. They may also have red eyes.


As dogs get older, they develop white and grey hairs just as humans do. These tend to first appear around the dog's snout, whiskers, and eyebrow regions. The older a dog is the more white hairs they will display and in more areas of the body. This method is not as useful with a naturally white dog, however. Older dogs may also show hair loss.

Skin Bumps

Middle-aged and senior dogs often have lumps on their skin that are benign fatty masses known as lipomas. A dog that has one or more of these is probably an older dog.


As a dog matures, his behavior will change. A middle-aged dog will not likely have the bouncy exuberance of a puppy. Senior dogs may show more confusion and decreased activity levels with accompanying weight gain. They may also have more house training accidents. These are not behaviors exclusive to older dogs, but they can indicate your dog is closer to a middle to senior age range.


There are many dog diseases that tend to appear among middle-aged and senior dogs. Some of these conditions include cancer, heart disease, arthritis, and kidney disease. A young dog can develop any of these conditions, but it's very unlikely compared to the incidence in older dogs.

Your Dog's Age

Without a verified background history on a dog, it's not possible for a veterinarian to pinpoint an exact age for your canine friend. A veterinarian can, however, give your dog a thorough medical check-up and provide an informed medical opinion on your dog's most likely range of age. Your veterinarian can also help you understand how to care for your dog's needs based on his or her approximate age range.

How Old Is My Dog?