How to Tell the Age of a Found Dog

Okay, let’s talk about found dogs. It’s a whole thing, isn’t it? You see this lost soul, often scruffy, maybe a bit scared, and your heart just aches. You bring them home, or to a shelter, and the first thing everyone wonders, after checking for a chip, is, “Okay, but how old are they?” It’s not just idle curiosity either; knowing even a ballpark age makes a huge difference for vet care, training expectations, exercise needs, and honestly, just figuring out what kind of life this poor pup has lived and what their future might hold.

So, you wanna know how to tell? Right, let’s cut to the chase. There’s no magic wand, no little barcode on their ear giving you their birthdate. Especially with a stray, whose history is a complete blank. But you can get a pretty good idea by looking at a few key things, assuming they haven’t been through some kind of trauma or neglect that messes with these signs.

The absolute best indicator, hands down, is their teeth. This is the first place any vet, any experienced rescuer, is gonna look. Seriously, open that mouth (carefully, gently, especially with a scared dog). What you’re seeing there is a timeline.

Puppies (under 4-5 months): These guys have needle-sharp, baby teeth. All 28 of ’em eventually. They erupt in a fairly predictable order, starting around 3 weeks. If they have a full set of tiny, perfect white daggers, they’re very young. Like, very young. Probably under four months, maybe even younger if you can feel little bumps where permanent teeth are coming in. They lose these between 4 and 6 months, much like human kids lose theirs. You might even find a tiny one on the floor!

Young Adults (6 months to 2 years): Their adult teeth are coming in, all 42 of them. By about 7 months, they should have most, if not all, of their adult teeth. At this stage, the teeth will be brilliant white, clean, and sharp. No wear and tear yet. Maybe a tiny bit of tartar starting to form on the back molars if they’re closer to two, but mostly just sparkling clean. This is the prime-time smile.

Adults (3-5 years): Okay, now you’re starting to see some action. There’ll be visible tartar buildup, particularly on the canines and molars. The teeth won’t be quite as blindingly white anymore; they might be a bit duller. You might see some slight wear on the incisors (those little front teeth). They’ve been using these chompers.

Mature Adults / Seniors (5+ years): This is where it gets fuzzier, but still telling. Significant wear becomes apparent, especially on the incisors, which might look worn down or even missing. Heavy tartar and maybe some gum recession are common. Some teeth might be discolored, chipped, or simply gone. The condition depends a lot on diet, chewing habits, and whether they’ve had dental care, but generally, the more wear and tear, the older the dog. A mouth full of stained, worn-down stubs? Yeah, that’s a dog who’s seen a few summers, probably quite a few.

See? Teeth are like rings on a tree trunk, but for dogs. Though, full disclosure, not all dogs read the memo. Some breeds are prone to worse dental issues earlier, and some dogs just have naturally great teeth late in life. But it’s the best starting point.

Beyond the teeth, what else can you eyeball?

The eyes. Puppies have bright, clear, often intensely colored eyes. As dogs age, their eyes can start to show signs of wear and tear too. Around 6-8 years old, many dogs develop a bluish haze in their lenses called lenticular sclerosis. It looks cloudy, but it usually doesn’t affect their vision much, unlike cataracts which are opaque and do impair sight. A dog with prominent lenticular sclerosis is very likely heading into their senior years, or is already there. Cataracts could happen at any age due to illness or genetics, but they are more common in older dogs. Plus, older eyes sometimes just seem… softer. More knowing. Less frantic puppy-stare, more thoughtful gaze.

The coat. Ah, the coat. This is another one that isn’t foolproof but helps build the picture. A young dog’s coat is usually vibrant, full, and maybe even a bit soft like puppy fur. As they age, especially around the muzzle and eyes, white or gray hairs often start to appear. This can happen earlier in some breeds or even due to stress, but significant graying, particularly combined with other signs, points to an older dog. The coat itself might become thinner, coarser, or just less lustrous. My old guy, Max, he started getting a distinguished gray muzzle around age 7, maybe 8? Made him look like a wise old professor.

Their muscle tone and general body shape. A young, active adult dog (say, 1-5 years) tends to have lean, well-defined muscles. They’re usually at their physical peak. An older dog, perhaps 7 or 8 and up, might start to lose muscle mass, even if they’re not losing weight. Their body shape might change – they might appear bonier in some places, or they might put on weight more easily due to slowing metabolism, leading to a saggy belly or fatty lumps (lipomas). Puppies, bless their little hearts, are often a bit pudgy and awkward, all paws and belly, before they stretch out into their adult form.

Their energy level and mobility. This is maybe the most obvious outward sign, but also the most variable. A true puppy is a whirlwind of chaotic energy. They play hard, sleep hard. Young adults (1-4 years) are often bundles of boundless energy, needing lots of exercise and stimulation. As dogs age, their energy levels generally decrease. They might sleep more, be less enthusiastic about long walks or intense play. They might stiffen up after lying down, move a bit slower, or show signs of joint pain like limping or difficulty with stairs. Of course, a high-energy breed might still be pretty zippy at 8, while a couch potato breed might act like a senior at 5. And a dog who’s been neglected or injured might have low energy and mobility issues regardless of age. So, you gotta take this with a grain of salt and look at the whole picture. But generally speaking, if a dog is bouncing off the walls non-stop, probably young. If they’re content with short strolls and napping in sunbeams, likely older.

Combine these observations. Do they have puppy teeth and boundless energy? Almost certainly a young pup. Do they have worn down teeth, cloudy eyes, graying muzzle, and move a bit stiffly? You’ve got yourself a senior, or close to it. What if they have clean teeth but look kind of tired and gray? Could be stress, illness, or maybe they’re just one of those dogs who grays early but has great genes for teeth. This is where the art comes in, and why a vet’s opinion is gold.

Speaking of vets, when you find a dog, getting them checked out is critical anyway. The vet can give you the most educated guess on age, often looking at bone structure (especially in younger dogs and puppies, growth plates tell a story), overall health, and combining all the physical signs. They’ve seen hundreds, thousands of dog mouths!

The thing is, with a found dog, you’re starting a relationship based on unknowns. Not knowing their exact age is just one of them. It can be frustrating. “Should I be training them like a puppy? Or managing age-related health issues?” You adapt. If they act like a puppy, treat them like one, but maybe temper expectations if their teeth suggest they’re past that stage. If they act like a senior, respect that and give them comfort and gentle care, even if their teeth look younger than you expected.

Ultimately, the age is just a number, a data point. It informs how you care for them, sure. But it doesn’t define the dog’s personality, their capacity for love, or the bond you build. I remember taking in a scruffy terrier mix years ago. Everyone guessed he was maybe 5 or 6 based on his energy and slight graying. The vet looked at his teeth, checked him over, and thought he was closer to 8 or 9! Blew us away. He had the spirit of a much younger dog. We adjusted his food, kept an eye on his joints, but mostly just enjoyed his fantastic, quirky self for the years we had him. Knowing his age helped us prepare for potential health issues, but it didn’t change how much we adored him.

So, yeah, check the teeth, peer into their eyes, examine the coat, feel their muscle tone, watch their energy level and mobility. Put all those pieces together like a little furry puzzle. Get a vet’s input if you can. But remember, the most important thing you can give a found dog isn’t an exact birthdate; it’s a safe place, a full belly, and love. The rest, you figure out as you go. And honestly? Sometimes the mystery is part of the journey.