As the bond between people and animals continues to grow, pets have become important members of the family. If you adopt or rescue a dog, you may not know his birthday. But knowing your dog’s age allows you to better care for him/her. This can help you choose the best food, care, and exercise for your dog’s stage of life. But there’s a common challenge faced by almost every rescue or adoption: How old is my new dog?

Factors affecting a dog’s age

Breed and Size: Smaller breeds live longer than large dogs. In fact, small breed dogs age slower and are only considered senior dog breeds after seven human years, whereas larger dogs are considered senior dogs after five years of age. Another factor is the differences in the specific types of medical conditions that affect different-sized breeds.

Genetics: Some breeds have higher rates of hereditary illnesses and proclivity for certain medical conditions due to limited genetic variability in parent generations.

Many mixed-breed dogs have more genetic variability, which can reduce the risk of hereditary diseases.

Quick Tricks to Determine Your Pet’s Age

Here are some of the best tips veterinarians use in their practice to help pet parents understand the age of their new rescue or adopted pet.

Looking for His Past:

If you want to know how old your new rescue or adoption is, start by learning as much as possible about her history. Sometimes middle-aged or older pets will come with veterinary records, or at least a history of how long they have been with their previous owner or foster carer.

Look at His Teeth:

Your veterinarian can provide you with a rough estimate based on one of your dog’s physical characteristics: his teeth. A dog’s teeth can reveal the approximate age of the dog and are especially useful in determining the age of younger dogs.

3-4 weeks       The first baby teeth to appear will generally be the canine teeth.

4-6 weeks     Deciduous (baby) incisors (little teeth in the front) and premolars start to come in.

8 weeks        All 28 puppy baby teeth have come in. The only exception is that I find in very small breeds like chihuahuas or brachycephalic breeds like Pugs and Frenchies, that full eruption, or development, of baby teeth can be delayed by several weeks.

4 months       Baby teeth begin to fall out and adult teeth can be seen coming in.

5-7 months    During this time, adult canines, premolars, and molars are coming in. In most dogs, all permanent teeth are in and at least almost fully erupted by 7 months.

1-2 years      All teeth are fully erupted and nice and white and clean.

3-5 Years     During this time frame, without dental care, we’ll see dental tartar continue to develop on all teeth, possibly with some early gingivitis.

5-10 years      Without brushing and periodic dental cleanings at the vet, teeth show significant wear and may show signs of gum disease.

10+ years     If teeth are not cared for regularly and effectively, dental diseases will further worsen, including dental calculus build-up, gingivitis and root exposure. Teeth are likely to be missing or broken.

Check the Eyes:

Dogs with bright, clear eyes that are not cloudy or blue are likely to be under six years of age.

If your dog’s eyes are slightly cloudy or blue with no signs of white or opacity, they are probably between six and ten years old.

Older dogs over the age of ten may be visually impaired with white or opaque eyes.

These guidelines may be affected by environment, breed, and health. Some breeds are born with cloudy or blue eyes.

Examine His Fur:

As dogs age, the color, texture and thickness of the different types of hair on their bodies change.

If your dog doesn’t have white hair on his muzzle, he is probably less than five years old.

Some gray hair around the muzzle or face indicates age between five and ten years.

If you notice white or light-colored fur around a dog’s eyes, muzzle, or chest, this may indicate that he has entered an advanced stage of life.

Older dogs also usually have thin or patchy fur, especially on the belly or lower back. Their skin may also be dry or flaky and lack softness.

Notice His Mobility and Activity Level: 

As our companions’ age, their excitement and stamina decrease.

An energetic dog that shows no signs of fatigue or boredom may be younger than five years old.

Dogs with moderate energy and endurance and some signs of fatigue or boredom may be between five and ten years old.

Dogs with low energy and easy boredom or fatigue may be over ten years old.

Your pet’s posture or gait is another factor to consider: older dogs may find it more difficult to sit, stand, or walk. Dogs with arthritis are most likely 6 years old or older.

As our pets age, many of us wonder how old our dogs are compared to the human lifespan. You can estimate its age with the five tips above. But this is only a rough estimate of age and may not be accurate. Why don’t you try these tips first and then talk to your veterinarian who can give your dog a thorough examination and run some tests if needed?