How to Tell How Old a Stray Dog is [7 Surprisingly Accurate Methods]

If you’re trying to figure out how old a stray dog is (in human years, not dog years), we have good news and bad news. Let’s start with the bad news. If you don’t know anything about the dog’s history, it’s nearly impossible to figure out exactly how old it is. The good news is that you can get a rough estimate of how old they are by analyzing some of their physical features.

Knowing Their Stage of Life

Because of the massive difference in lifespans, throughout this article, we will be talking about “stages of life” instead of exact ages. We can’t say “here’s the physical attributes of an eight-year old dog” because for a small dog eight years old might still be considered prime adulthood, whereas, for a large dog, it might be regarded as elderly.

The three stages of life your dog will go through are the puppy phase, the adult phase, and the senior phase.

The goal with this article isn’t to help you figure out the exact age of a dog (in calendar years, not dog years), that’s impossible. We want to help you figure out approximately how far along your dog is in each stage of life. The more aware you are of your dog’s approximate age, the better you’ll be able to take care of them.

How To Tell How Old Your Puppy Is

You can get a very good rough estimate of how old a puppy is if they are between 0-28 weeks of age by merely analyzing their teeth. Regardless of breed, dog’s teeth have very similar for the first eight weeks. Of course, if your pup was born with dental disease, it makes things more complicated. But for a typical, healthy pup, here’s what you can expect.

Tooth Development From 0-8 Weeks

• 0-2 Weeks: No teeth will be visible
• 3-4 Weeks: Canines will begin to appear
• 4-6 Weeks: Incisors will begin to appear
• 6-8 Weeks: Premolars begin to appear

Weeks 8-16: Watch For Teething

Weeks 8-16 create more of a challenge than weeks 0-8. The reason for this is because nothing major in development happens between these weeks.

This is where most puppies exit phase one of their puppy phase and enter phase 2 – the teething phase.

It typically happens anywhere between the weeks of 8-16. Again, small dogs develop quicker than larger dogs such as a great dane, so if your dog is a small dog expect teething to begin around weeks 8-10. If you have a large breed, expect teething to start around weeks 14-16.

Let’s say I have a Boston Terrier (small dog breed). Once they begin teething, I can safely assume they are between 8-10 weeks old. If I have an Australian Shepherd (large dog breed), once they start teething, I can safely assume they are between 14-16 weeks old. If you aren’t sure whether your dog would be classified as big or small when fully grown, just google search a chart for the sizes of dogs.

Weeks 16-28: Watch For Adult Teeth

By the time a puppy is 16-20 weeks old, their baby teeth (milk teeth) will begin falling out and will be replaced by their adult teeth (permanent teeth). Their canines will fall out first, and over the next 4-8 weeks that will be followed by the incisors and molars.

Most small dogs should have all their adult teeth between the weeks of 18-22, and most large dogs should have their adult teeth by the weeks of 25-28.

At this point, your puppy begins to go from being a puppy to being an adult dog. Assuming your dog wasn’t born with any diseases, you can use the teeth to semi-accurately determine how old your puppy is.

How to Tell How Old Your Adult Dog is

It’s relatively easy to tell how old a puppy is. On the other hand, it’s a real challenge to determine the age of an adult dog. Instead of trying to get the exact age, you’ll want to figure out if your dog is in their young adult years or approaching their senior years. Below are a few things you can do to help you get a general idea of how old your adult dog may be.

You’ll notice we didn’t include checking the teeth in this list for adult dogs. The reason for that is because some dogs have had different levels of dental care than others. Trying to determine an adult dog’s age based on their teeth is an unreliable method.

If your dog is six months of age or older, give the following methods a try.

Compare Photos

This is by far the best way to determine how old your adult dog is. Ironically, it’s also the one that’s never talked about!

Assuming a dog is properly taken care of, breeds look very similar at the same age. For example, let’s say you have a black lab. You know it’s no longer a puppy because it has a full set of adult teeth. Just go to the internet and do an image search for “2 year old black lab”. Then do the same with 3 year old, 4 year old, and so on.

Compare all the images and figure out which one looks most like your dog. There’s a good chance your dog is somewhere around that same age.

Do They Have Clear Eyes?

A young, healthy adult dog will have clear eyes. A dog that is middle-aged may start to develop cloudy/foggy eyes that appear to give off a blue reflection (lenticular sclerosis). Dogs entering their senior years of age typically develop cataracts, which makes it difficult to see.

With all that said, it’s essential to keep in mind that younger dogs can develop eye problems such as glaucoma, which looks a lot like cataracts. So be sure to use this in addition to all the other methods we will discuss below.

Do They Have Grandpa Fur?

If your dog doesn’t have any gray hair, that’s a sure sign that they’re in their young adult years. However, if they are getting gray hair on spots across the entire body, that could be a sign they’re entering their senior years.

Gray hair doesn’t always mean old. Stress at a young age can cause changes in a dog’s physical appearance, just like it can for humans. Dogs that have lived a stressful life will gray early in life, especially around the snout and eyes.

If that’s the only gray you see, and they still have relatively clear eyes, they’re probably still in their younger adult years. If they have cataracts along with the gray hair, you know your dog is in his senior years.

Do They Have Muscle Tone?

A young/healthy adult dog should have visible muscle tone and minimal fat. Even bigger dogs that tend to carry more fat (like a bulldog) should have noticeable muscle tone. When a dog reaches middle age, they’ll slowly start to lose muscle tone and put on a little fat. When a dog reaches their senior years, many of them will refuse to eat as much as they used to. This results in a loss of both muscle and fat. So middle age dogs tend to be a little more plump, and older dogs look frail.

Mobility and Activity Level

When you call your dog, how long does it take for them to get up and come to you? Do they jump right up and run straight to you? Or do they take their sweet time getting up and then look at you, as if to say “do you REALLY need me to come over there?!”

Younger and middle age dogs show a lot of excitement when their owner calls their name. An older dog doesn’t display this type of excitement. It’s not that they aren’t excited to come to you, but at this point, they’ve likely developed arthritis in their hips, which makes it difficult to stand up and walk.

Do They Have Bumps On Their Skin?

Have you ever pet an older dog and felt a couple of bumps on the skin? This is called lipomas (fatty tumors). They’re nothing to worry about, but they are a sign that a dog is in its final years. Most of the time, the lump is not cancerous, but it’s still a good idea to take your dog to the vet when new lumps develop to be on the safe side. If your dog has smooth skin, they’re probably in their younger adult years.

The Importance of Determining Your Dogs Stage of Life

I know we all want to know the exact age of our dogs, but the truth is unless you have information on them from when they were a puppy, there’s no way to figure out the exact age. Even getting a complete blood profile done on your dog can’t accurately predict the age.

However, it is possible to figure out if your dog is in its early adult years, middle-aged, or in its senior years. This is important to know because it will change what you feed them, how often you take them out on walks, how often you take them to the veterinarian, what to look for in regards to signs of aging, and so on.

The methods mentioned above to estimate a dog’s age are the exact methods a vet would use. However, if you aren’t sure in your ability to perform the analysis, you can always take your dog into the vet and have them do it for you.

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