Do Dogs Know Each Other’s Age?

do dogs know each others age

It is very common to see a well-socialized dog interacting with another dog to change its behavior depending on the other dog’s age. A dog might be gentle but firm with a very young pup, be a bit sterner with an older puppy or exuberant adolescent, or be more submissive and gentle to an older dog.

So is it guesswork on the dog’s part or do dogs actually know each other’s age?

The short answer is yes, dogs do know each other’s age. Through each different developmental stage, puppyhood, adolescence, and adulthood, a dog’s behavior changes. Dogs even treat each other differently according to what age and life stage they might be at themselves. 

So while it might be obvious that dogs know each other’s ages, how can they tell?

There are several ways for dogs to tell each other’s age. Their sense of smell is one of the most effective ways a dog can tell the age of another dog, but other sensory cues include visual and auditory perceptions. Our dogs not only enjoy heightened senses but can also take cues from another dog’s behavior (behavior can change drastically depending on their developmental stage).

Let’s explore how a dog uses their senses and other dogs’ behavior to determine each other’s ages.

What Are Some Sensory Cues That Help Dogs Know Each Other’s Age?


Have you ever heard the term “pee-mail?” The idea is that without ever meeting the other dog, a dog can smell another dog’s urine and know when they were there, whether they were male or female, and even the other dog’s age. Dogs have over 220 million scent receptors in their nose, and the pheromone and hormone scents they can pick up in each other’s urine can help them determine a wealth of information about one another.

Many dogs, and especially puppies, will often roll on their back in appeasement and urinate just a little when an older dog is interacting with them. By smelling that dog, the other dog can pick up certain hormones that inform them whether that dog is a puppy, adolescent dog, or adult dog.

Visual Cues

Size is not always indicative of the age of a dog. An adult teacup Chihuahua is obviously older than a twelve-week-old Golden Retriever, even if the chihuahua is technically much smaller. But size is not the factor that shows the age of a dog. Puppies move differently than adult dogs, and senior dogs move differently than middle-aged dogs.

A puppy will often be clumsy since they are still figuring out where their feet and legs are and how their body moves. An adult dog in its prime usually moves with some gracefulness and confidence, whereas a senior dog might walk stiffly because of old-age-related ailments.

Using these visual cues of size and movement, along with being able to smell hormones and pheromones, a dog will certainly be able to know each other’s ages.

Audio Cues

Between barking, whining, and growling, the many different vocal communications dogs have with each other help give certain information about temperament, mood, and age. According to one study, a dog can even tell the size of another dog just by hearing the other dog’s growl.

Dog noises change as they age, from small puppy whimpers and yips to a larger adult dog’s booming bark and intimidating growl. Even a smaller dog like the Chihuahua’s bark has a different tenor than the twelve-week-old Golden Retriever. This video is a compilation of the same Rottweiler and how his barks and howls change from the squeaky yips of a puppy to the deep bark of an adult dog.

So what if a dog cannot see or smell another dog and maybe can only hear it through a fence or door? There is a good chance they still can know each other’s ages simply by being able to hear the other dog. Their individual vocalizations and the pitch of the noises they make can help give information on how old they are as the sound of vocalizations can also change with age

Behavioral Cues In Puppies And Adult Dogs

Anyone lucky enough to raise a dog from puppyhood to adulthood knows how drastically their behavior changes with age. Dogs are probably even more in-tune with the behavioral cues that accompany another dog’s developmental stages. The behavioral cues give dogs important information to help them determine each other’s ages. 

Can Dogs Tell If Another Dog Is A Puppy?

As we have already mentioned, dogs are aware that another dog is a puppy just by being able to smell, see, and hear it. Puppies also give significant behavioral cues that let older dogs know their age. When meeting new adult dogs, puppies are usually incredibly energetic, they test boundaries, and they have no sense of personal space.

Often, an older dog will correct a puppy by growling, avoiding it, or maybe snapping at them. The older Labrador in the video below seems to know that the other dog is a puppy by looking (and probably smelling), and when the puppy gets rambunctious the older dog paws and physically moves away just like an older dog might behave with a crazy puppy:

These are very normal behaviors, both for the puppy and the more mature dog. The puppy has shown the older dog how much younger they are by their over-the-top behavior, so the older dog is reasonably showing boundaries. Often, after being corrected, a puppy will roll over submissively and might even urinate a little. As we have already learned, by smelling the puppy, an older dog has another clue about the age of the other dog. 

As the puppy becomes an adolescent, and they learn more about the world, the older dogs might not be quite as patient. They are helping socialize the younger dog and letting the puppy know it is annoying. If they seem to be less gentle than they were when the puppy was tiny, it is because they are aware of the dog’s age and that they are getting older, and can handle firmer boundaries.

Remember, some dogs are more patient with puppies than others, so be aware of how they will react before introducing a new dog into your household.

Do Dogs Know If Other Dogs Are Old?

Through smell, visual cues, and auditory cues, a dog knows if other dogs are old. Their hormones and pheromones will change, they may become more vocal and move differently if they are stiff or sore. Growing old can have an effect on their behavior as well, specifically moodiness, confusion, or impatience.

They will also be less playful. Most other dogs can pick up on these changes. A well-socialized dog will read the older dog’s body language to determine if they can visit or not.

In Conclusion

When I observe my three-year-old border collie’s behavior with other dogs, I see she is very gentle with puppies, plays rough with adolescent dogs and other dogs her age, and is extremely submissive to older dogs. It is very easy to anthropomorphize my dog and just say that she is intuitive about knowing other dogs’ ages.

But between smelling, hearing, and seeing other dogs, she probably does have a good idea of what age the other dog is. She will change her behavior accordingly and interact with the other dog depending on their age.

Dogs can use both sensory cues and behavioral observations to help them know what each other’s ages are. Make sure you socialize your dog to help them understand how to interact with other dogs of all ages, whether it is a puppy or a senior dog. 

Remember to know your dog and adjust your expectations since not every old dog might have the patience for a rambunctious puppy, and not every puppy might be able to control themselves around a grouchy geriatric dog.

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