3 Big Clues to How Old is My Dog?

The first question most people ask about your dog is what breed he is. The second question is, how old is he? But when adopting a dog, we don’t always know the dog’s history.

Dog rescues and humane societies usually take a guess based on certain physical appearances. It can be difficult to know how to tell how old a stray dog is.

While you may never know your dog’s exact birth date, there are several physical attributes to look for that can give you a good estimate of how old your dog really is.

All of these vary based on your dog’s breed, nutrition, and medical history.

Our first foster dog, Silla, was an owner surrender, so we did know her age… she was 10 years old. The vet was actually shocked to learn how old Silla was because her teeth were still pearly white, which is very rare for a dog her age.

So how can we tell the age of an adopted dog? Here are three big clues to help you guess as close as possible:

1. Teeth: The Most Reliable Indicator

A dog’s teeth change significantly as they age, making them one of the best ways to estimate their age. See the chart below:

By the time your dog is about 4 months old, his adult incisors, canines, and premolars should be coming in. When your dog is about 6 months old, all of his baby teeth should be gone.

If your puppy has any baby teeth left, he is most likely younger than 6 months old.

If you have adopted an adult dog, it is going to be more difficult to determine age by his teeth. But you can guess that the more tartar builds up, the older the dog is. If his teeth are pretty clean, my guess would be he is younger than 3 years old. The above photo is of our 3-year-old yellow lab.

2. Is your dog turning grey?

This one is pretty simple; just like humans, dogs can turn white or grey as they age. Usually, around 5 years old, you will notice some graying around your dog’s face and muzzle. But greying is not always an accurate sign, as some dogs have been known to start graying as young as 2 years old.

3. Observe your dog’s eyes.

Gaze into those beautiful puppy eyes. This is something I never knew before, but as your dog ages, his eyes develop lenticular or nuclear sclerosis. It looks like a haze or grey film over the eye.

And as your dog gets older, the gel inside the lens becomes thicker, hardens, and changes color. This graying in their eyes usually starts around 5 years old and becomes more prominent as the years pass. There is a great article on PetMD, Is it a Cataract or Lenticular Sclerosis?

If you are concerned at all about your dog’s eyes, I recommend taking him to the vet to have it checked out.

With these three clues – teeth, coat, and eyes – you can get a good estimate of how old your dog really is. But you also need to consider the breed of your dog. Larger dogs age more quickly than small dogs.

Dog Years Versus Human Years

So now that you have an idea how old your dog is in dog years, you may be wondering how old is my dog in human years?

How long is a dog year anyway?

I found it interesting that the common theory that one human year equals seven dog years is not true! I believed this my entire life until recently!

It turns out that a one-year-old dog is one in dog years but 15 in human years. Wow, that’s some quick maturing. This goes for all sizes of dogs.

But after about 5 years old, the conversion changes based on the size of your dog. Below is a great dog years converter chart to show how old your dog is in human years:

Dog Years Converter Chart

Now that we have dog years explained clearly, enjoy every day, every month, and every year you have with your dog. Time passes so quickly!

Keeping your dog happy and healthy is the most important part of your life together. Feed them high-quality food, bring them to the vet for yearly checkups, and give them plenty of exercise and love.