How Can You Tell the Age of a Rescue Dog?

Rescues and shelters rely on whatever information they can get from the previous owners plus the shelter vet’s best estimate. Any dog that’s no longer a puppy but seems like they aren’t yet in the senior category gets labeled an “adult dog,” which in reality, can be age 1-8.

On top of that, different breeds and breed sizes age at different rates. Small dogs like Chihuahuas tend to live longer than large dogs, but they also reach maturity faster. For instance, a Chihuahua stops growing around 9 months. Golden Retrievers, on the other hand, won’t reach their adult weight until 1-2 years.

All of this makes it pretty hard to determine an adult shelter dog’s true age. Of course, you can always celebrate their birthday in August for Dogust, even without knowing their exact birth date. However, here are a few tricks you can use to make your best guess.

How to tell a dog’s age by their teeth

The most common method that veterinarians have relied on is checking out a dog’s teeth. If you’re interested in a certain dog at the shelter, you may also be able to use this method as long as the dog is okay with people checking out their teeth. 

It’s also useful when you’ve already adopted a dog and want to try to determine their age. Of course, it’s not precise by any means, but it will usually get you in the right life stage and approximate age.

Here’s what a dog’s teeth will look like at each life stage:

Puppy teeth (up to 1 year):

You’d probably be able to recognize a young puppy just by looking at them, but it gets harder to tell once they get their adult teeth in, which happens around 6 months. From 6 months up to a year, though, their teeth will still be pretty white and clean.

Adult dog teeth (age 1-4):

When dogs get to be about 1-3 years old, their teeth will turn from white to dull, with yellowing teeth toward the back as tartar starts building up. Small breed dogs may even start to develop dental disease as early as 1 year of age.

Teeth of older adult dogs (age 5-8):

Around age 3, most dogs (80-90%) have some level of periodontal disease. It’s more visible in advanced stages, but you’re likely to see red gums. You’ll also be able to spot more tartar buildup (now orange or brown) and wear and tear on the teeth in older adult dogs. 

Signs of senior dog teeth (over 8):

By this time, you may see advanced dental disease, with red gums, worn teeth, yellow teeth covered in tartar, and even missing teeth. One big clue is also if they have bad breath.

Looking at a dog’s teeth will give you an estimate of their life stage, but your vet will be able to more accurately determine an age range.

Other ways a dog’s body will show their age

You can also tell a dog’s age, or at least their life stage, by the way they move and behave, subtle signs in their coat and eyes, and their overall appearance.

Behavior: Check out the dog’s energy level and behaviors. Young pups will be super playful, and if they haven’t had any training, they might be barky and jumping up a lot. They also love to chew, especially when they’re teething, but also just because they’re puppies and trying things out. Keep in mind that bigger dogs will act like puppies for longer, even up to 2 years.

Muscle Mass and Movement: Older dogs lose muscle mass and can have bony spines or other spots. You can usually see this in their upper legs or back. This could be due to being less active and energetic, causing the muscles to shrink. Arthritis can start in dogs around age 7 or 8, and this can really slow a dog down and make them seem stiff when they walk.

Eyes: If you suspect that a dog may be a little older than middle-age, check out their eyes. Senior pups often get a cloudy look to their eyes, and it doesn’t necessarily mean they have cataracts. There is an age-related haziness that dogs get called lenticular sclerosis where the lenses of their eyes may look blue or gray. Of course, you should always get a newly adopted pup checked out if they have cloudy eyes.

 Coat: A dog’s coat also changes as they age. Around the age of 6 months to 2 years, dogs will shed their puppy coats for their adult fur. This should be a strong, full coat, and some breeds will develop a double coat. It should look and feel healthy. As they get to be older adults (over 7), their coats may start getting thin, dull, or coarse, and they’ll start to get gray hairs around their nose and paws. Speaking of paws, younger pups will have smoother paws, while older dog paws will be rougher.