How to Determine a Dog's Age

A dog's teeth provide excellent clues to his approximate age.
alaskan malamute image by devilpup from

Knowing your dog's age can help you anticipate any age-related health needs or problems. You can also have a rough idea of her remaining life expectancy. Beyond the first year or two of life, the saying about a dog year equating to seven human years holds roughly true: A life expectancy of 70 years for a human or 10 years for a dog is quite common. If your dog was abandoned, rescued or found as a stray, you may have no reliable records or documents stating her age. Some detective work can help you estimate your dog's age in years or her stage in the canine life cycle.

Step 1

Examine your dog's teeth. Typically, a puppy has a full set of baby teeth by the age of 8 weeks. These deciduous teeth are replaced by clean, white permanent teeth between the ages of 2 months and 7 months. If your dog is 1 or 2 years old, her teeth will start to be dull at the back, and might show some yellow discoloration. Between 3 and 5 years of age, a dog's teeth are typically somewhat worn, and tartar buildup may be evident. Teeth become significantly worn between the ages of 5 and 10 years, and beyond 10 years of age most dogs have worn teeth and significant tartar buildup. Missing teeth may be a sign of accident, injury or old age, but many dogs also are born with some teeth missing.

Step 2

Observe your dog moving around the indoor or outdoor environment. If he moves stiffly and slowly, that is a sign that your dog is most likely in the second half of his expected natural lifespan. Just as humans commonly experience problems such as arthritis in later years, dogs' skeletons typically become weaker and stiffer as they age. However, a young dog may move stiffly or awkwardly if she has suffered an injury in the past.

Step 3

Look at your dog's coat and skin. Like humans, dogs usually develop gray hair as they age. Normally this happens by the time a dog is around 7 years old, but some dogs may go gray at an earlier age. Typically, gray hair starts to develop around the dog's muzzle, spreading around the facial area, head, and then the full body. Another clue to age is in the tautness or elasticity of the dog's skin. Younger dogs typically have more elastic skin than older dogs.


  • In general, small dogs have a longer life expectancy than large dogs.

  • Older dogs commonly develop cloudiness in the eyes.

  • Any documentation relating to your dog -- old rabies tags, partial veterinary records, or even date-stamped photos of the dog in family photos -- can help you estimate his age in years.

  • Your veterinarian may be able to estimate a dog's age as part of a full physical examination.


  • American Kennel Club: Aging Dogs
  • Dog Age: How Young is Your Dog?; Dondi S. Dahlgaard
  • Dog Owner's Home Veterinary Handbook; Debra Eldredge, Liisa D. Carlson, DVM, Delbert G. Carlson, James M. Giffin

About the Author

Jae Allen has been a writer since 1999, with articles published in "The Hub," "Innocent Words" and "Rhythm." She has worked as a medical writer, paralegal, veterinary assistant, stage manager, session musician, ghostwriter and university professor. Allen specializes in travel, health/fitness, animals and other topics.

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