How old is my dog?


You might be surprised to learn the 1:7 ratio of a dog to human years is a myth! The aging process actually depends on the dog’s size, breed and health. On average, large and giant-sized breeds age faster than small and medium-sized breeds. However, some breeds like Frenchies and Pugs are outliers because of their inherited illnesses, so they age faster compared to other medium-sized breeds.

Not only is it fun to know where our furry best friends are in life compared to us, but when it comes to your dog’s health, their age is a huge factor in determining what type of care they need.

Follow our guide to determine how old your dog is if their age is unknown, what life stage they’re in and how old they are in human years.

What if I don’t know how old my dog is?

The best way to find out the accurate age of your dog is to get your pet’s microchip scanned at a veterinary clinic or shelter. The information stored in their microchip may reveal the original breeder or owner of the pet, who may have details about your dog’s age, medical history, and other important information. 

However, many pets arrive at shelters without a microchip or their owner’s information isn’t registered, making it impossible to find out the pet’s exact age.

In this case, a veterinarian can provide you with a rough estimate based on your pet’s teeth.

Similar to humans, dogs have two sets of teeth in their lifetime. As a puppy, they will get 28 baby teeth and 42 permanent teeth as an adult.

Dogs aren’t born with teeth, but they will get all their baby teeth in the first two months of their life and their permanent teeth by the time they’re seven months old.

The older a dog gets, the more tartar, teeth loss and disease they will have. For example, a 1-to-2-year-old’s teeth will start to appear dull with some tartar. While a 10-to-15-year old’s teeth will be worn, show heavy tartar build-up and might have some teeth missing.

That being said, this estimate might be impacted if the dog has a history of excellent dental care.

Use our dog age chart below to try finding out your dog’s age at home:

Estimated Age: Dog's Teeth:
2-4 weeks No teeth growth
3 - 6 weeks Baby teeth start coming
8 weeks All baby teeth are in
3 1/2 - 4 months Permanent teeth start coming in
7 months All permanent teeth are in
1 year Teeth appear dull with some tartar build-up (yellowing) on black teeth
3 - 5 years Tartar build-up on all teeth and some tooth wear
5 - 10 years Teeth show increased wear and disease
10 - 15 years Teeth are worn and show heavy tartar build-up, some teeth may be missing



Source: Rural Area Veterinary Services

What stage of life is my dog in?

A dog goes through four stages in their lifetime. These stages don’t depend solely on age, but size, breed, health, and behavioral development. The American Animal Hospital Association (AAHA) defines these stages as: puppy, young adult, mature adult and senior.

  1. Puppy: Birth to 6-9 months (When your puppy stops growing)
  2. Young adult: 6- 9 months to 3-4 years (Your dog has calmed down)
  3. Mature adult: 3-4 years to the beginning of last 25% of estimated life span (depending on breed and size)
  4. Senior: Last 25% of estimated lifespan to end of life
    • For giant breeds, the senior stage starts at 6 years, but for smaller breeds, it may not start until 12.

Dog years to human years

It isn’t as simple as the one dog year = seven human years rule that most people know. Unlike humans, the aging process follows a curve versus a straight line and a dog’s age depends on its breed and size.

Between birth and one year, most dogs mature to an equivalent of 15 human years. While they only mature four human years between 8 to 9 years old.

Find out your dog’s age in human years with American Kennel Club’s chart below:


Source: Rural Area Veterinary Services

What type of care does my dog need?

Although visiting the veterinarian every 6 to 12 months is recommended to keep your dog healthy regardless of their age, they might need more frequent check-ups or receive different treatments based on the life stage they are in.

A puppy will make more frequent visits to get their vaccines, deworming, and monitor their growth. They may get spayed or neutered at this stage too.

As a young adult, your dog will receive appropriate protection against fleas, ticks, and heartworms. They will also be monitored for healthy weight and dental wellness.

As your dog gets older, they are more prone to developing health conditions such as arthritis, heart, kidney and gum disease or cancer. If your pet develops any of these issues, your veterinarian may recommend that you bring them in more frequently.

Ultimately, the frequency of visits to your veterinarian will depend on your dog’s health throughout their entire life and if any emergencies come up.

Now that you know your dog’s age and life stage, ask your veterinarian what type of care your pet needs and how you can help them navigate the special part of life they’re in. Did you know that 24Petwatch offers access to a 24/7 vet helpline for 1 year with our Lifetime Protection Membership? Click here to learn more.

Share this article with other pet parents to help them discover their dog’s age and life stage. 

Author Bio