Skip to main content

Do Dogs Really Smile?

Yep — but there are big differences between smiling, grinning, and showing teeth.

by Karen B. London, PhD
March 30, 2021
Dog in the sand smiling at the camera
Photoboyko/Adobe Stock

Sign up for The Wildest newsletter for updates

One of my favorite private consultations of all time involved a family who came to me, scared and sad, because they were worried about the way their beloved Golden Retriever was acting toward their two-month-old baby. Though the dog had been a total angel for more than four years, they were afraid they would have to rehome, or perhaps even euthanize, him. “Our dog has gotten aggressive and is showing his teeth to our daughter,” my clients said. 

When I met their dog during our appointment, I couldn’t reconcile my immediate impression of his docile nature with a dog who was threatening a baby. My clients described how the dog showed his teeth ever-so-briefly whenever they brought their daughter into the living room after a nap, when he first saw her each morning, and when they came home with her after an absence. 

Because the teeth showing was always in greeting and because their dog seemed about as threatening as a butterfly, I suspected that the dog was smiling, but needed to know for sure. I couldn’t afford to be wrong; a baby’s safety depended on my understanding and assessment of the situation.

I had the family step into the hallway with the baby for a few minutes, and then return to my office. And that’s when I saw it: a lovely smile by a lovely dog. It was accompanied by a loose body, a gentle but enthusiastic tail-wag, a relaxed face, and what I can only describe as an adoring gaze.

Thankfully, there was no need to be the bearer of bad news. Though these clients came to me about what they thought was an aggressive dog, I was able to tell them, honestly and joyfully, that their dog wasn’t aggressive at all, but rather, social, sweet and gentle.

In other words, their fears were misplaced. Even though the dog was regularly pulling his lips back and revealing his teeth, he wasn’t acting in an aggressive manner. (We did, of course, discuss some standard baby-related issues including that all dogs and babies need supervision and can’t be left alone together.)

So, what was this dog doing? He was performing a behavior called smiling, which — just as when humans do it — involves showing some teeth.

Get your fix of The Wildest

We promise not to send you garbage that turns your inbox into a litter box. Just our latest tips and support for your pet.

There Are Two Types Of Dog Smiles

What most of us call a dog smile is really a grin — a happy, open-mouthed face of a jolly dog. In this “happy grin” kind of smile, which can last for minutes, the lower jaw hangs open and the corners of the lips are pulled back in a relaxed way. Sometimes the tongue hangs out, or is at least visible inside the mouth. Though the bottom teeth often show, the top teeth aren’t likely to.

The second type of smile (the one discussed above) is a retraction of the lips that reveals the top and usually the bottom teeth as well. Because it resembles an aggressive expression called a “tooth display,” it can freak people out. However, this kind of smile has absolutely nothing to do with aggression. In fact, it's a social expression.

These smiles are different from tooth displays or big grins. Both tooth displays and smiles reveal the upper teeth (and sometimes the lower teeth), but in contrast to tooth displays, smiles happen quickly and are subtle. The upward movement of the lips away from the teeth is often slight, and the retraction rarely lasts more than a second. The combination of minimal movement and speed makes it a challenge to capture them photographically. You have to be at exactly the right angle and height, which is difficult when a dog is moving around, often wagging not just the tail, but much of the body, as is so often the case when dogs smile.

Tooth displays, on the other hand, are usually performed by a dog who’s fairly stiff and still in both body and face. The showing of the teeth proceeds more slowly, and the expression can last for several seconds or more. Tooth displays are often an indication that a dog has been pushed past their comfort zone, perhaps by the approach or touch of another dog or a person, when they have a treasured object, or when they’re exhausted/in pain and want to be left alone.

More On The Smile

Whenever a dog smiles in this fleeting, friendly, social way, I’m delighted. In my opinion, it reveals many positive qualities about that dog, and about the relationship between the dog and the recipient of the smile. Smiling dogs tend to be social, affiliative, and loving.

That said, I’m not aware of any scientific studies that explore the meaning and context of such smiles. So, I base this opinion (and this discussion) on my own experience with smiling dogs, as well as discussions with other dog trainers and behaviorists over the years.

Smiles are often given when greeting people the dog adores, especially if the dog hasn’t seen the person for some time. The smiles seem to indicate that the dog is over the moon (to use a nontechnical term!) about the reunion, and about the opportunity to greet the person.

I used to think these smiles were a sign of a dog who was slightly conflicted during a greeting — nervous and excited, or perhaps interested but also cautious. However, I’m no longer convinced that’s true. Recently, I had an opportunity to observe this behavior first-hand. 

Roxy, a Great Pyrenees/Poodle mix who stayed with us while her family was traveling, took turns sleeping with different family members. Each morning, she’d smile when greeting those whose room she had not slept in; she’d also smile when one of us came home after a few hours out. Her biggest smiles, however, were on display when her family returned from a month-long trip. She was absolutely thrilled to see them.

I recently discussed what ethologists (aka, animal behaviorists) call smiles with Chelse Wagner, a certified behavior consultant and dog trainer at Dog’s Best Friend Training in Madison, Wisc. When I first started working as a dog trainer, I assisted in Chelse’s training classes, where I learned a lot from watching her work with dogs and people. She has several decades of experience working with dogs in shelters, as a trainer, and as a canine behavior consultant.

Chelse pointed out that while dogs displaying a smile tend to have loose bodies, they will often hold their ears back and keep their body lower to the ground; this can make them seem ambivalent or conflicted, rather than happy. Chelse has lived with two dogs who smiled this way: one was an exceptionally social Greyhound named Sage, whose smile was more likely to appear and more likely to be exaggerated the longer someone had been gone. The other dog, a mini Aussie named Charlie, smiled more when he was younger than he does now. Charlie was especially likely to smile at Chelse’s husband, perhaps (as she suggests) because he was the first to be gone for extended periods.

It has been suggested that dogs who smile learn it from humans. The action of smiling is very common among primates, including humans, and it is highly possible that dogs are copying us. This implies that dogs who smile have good social skills, which fits with my experience. I cannot think of a dog I have seen smile who is not social. Nor can I think of any dogs I’ve seen smile who were prone to arousal or getting out of control in play, greetings, or other social settings. That being said, I haven’t seen a ton of dogs who smile this way. But, given its fleeting nature, I’ve likely missed seeing it even when it was present.

If dogs do indeed learn to smile from people, then that means they have a strong connection to us and are capable of mimicking our behavior. It also accounts for the smile’s vaguely awkward and unnatural presentation. (Dogs who smile remind me of small children who are asked to smile for a photo but don’t know how to offer a natural smile that reflects genuinely happy feelings.)

A Good Result

The couple with the young baby and the smiling Golden Retriever were considering rehoming or even euthanizing their dog because they feared for the safety of their child. Imagine their joy — and mine! — when I was able to tell them that he was just smiling, and explain what that meant. He was a sweet, social dog, as they had always thought, and his toothy behavior was an ecstatic greeting rather than a threat.

Without knowing for certain what was in that dog’s heart, I could say with confidence that it appeared from his behavior as though he loved the baby. No wonder this consult stands out as one of my all-time favorites!

Related articles

karen london

Karen B. London, PhD

Karen B. London, Ph.D., is a Certified Applied Animal Behaviorist and Certified Professional Dog Trainer who specializes in working with dogs with serious behavioral issues, including aggression. She writes the animal column for the Arizona Daily Sun and is an Adjunct Professor in the Department of Biological Sciences at Northern Arizona University. She is the author of six books about canine training and behavior, including her most recent, Treat Everyone Like a Dog: How a Dog Trainer’s World View Can Improve Your Life.