What Is the True Definition of a Dog Smile?

A smile can definitely tell us how a human feels, but a smile isn’t the best indicator of a dog’s emotional state. Instead, we look for a wagging tail, a wiggly body, and an energetic attitude. But, let’s be honest, there are times when a dog appears to be wearing a big ole grin.

So, when is a dog actually smiling? There’s no definitive scientific answer to this question. It’s a human tendency to project our own behaviors and feelings onto animals when they may not actually apply. Moreover, each dog expresses herself differently—a single look doesn’t mean the same thing on every dog.

That said, there are a few ways to think about what it means when our dogs show us their pearly whites. Sometimes we’re seeing the submissive grin, sometimes the snarl, and sometimes the smile.

All About Dog Smiles

The Submissive Grin

This looks something like a smile because a dog will show its teeth. But it’s actually a gesture of submission, fear, or social awkwardness. The dog will lift the front part of his lip below the nose, exposing the front incisors.

This can happen when a dog encounters a larger or more dominant dog, or when a new situation arises and the dog isn’t sure what to expect. Sometimes a dog may be confused by a new situation and she will make this expression as a catch-all backup plan. Like the teenager shrugging his shoulders. She may be saying, “Mom, what’s all this business? I seriously don’t know if I like it.”

You’ll find a few examples below. The first photo demonstrates what the submissive grin looks like, but gravity is doing all the work in this case. The Chihuahua in the second image is giving a true submissive grin. And in the video, Rubi the dachshund repeatedly makes this face, almost involuntarily, while her owner plants raspberries on her belly. Perhaps she’s thinking, “What is this?! I love it, hate it, love it!”

When you see this face, consider the full context of the situation, look for other body language, and take into account the dog’s overall disposition and behavior patterns.

The Snarl

This is a more familiar and truly defensive expression, a warning to other dogs to check themselves. It’s only slightly different in appearance from the submissive grin. With the grin, a dog lifts his front lip up like a window shade. With a snarl, the mouth pulls back and up.

You’ll often see this face on dogs who feel protective of their food, or when a new or smaller dog arrives on the scene and he needs to be put in his place. Some dogs use this face quite often, but you may never see this expression on a laid-back, happy-go-lucky pet.

The Smile?

While there is no technical definition for a dog smile, you tend know one when you see one. The dog looks relaxed and joyful. His mouth is open, his tongue is visible, and you see an upward curl at the fold of the lips. The dog’s whole being looks happy.

But is this proof the dog is blissed out and completely loving life? Maybe. It’s hard to know. Certain breeds, particularly those with smushed noses, look very smiley when they’re panting or tired. Pugs have a naturally smiley face, for example, but they’re also generally easygoing dogs. The Shiba pictured above seems to have been born with a giant smile.

The Bottom Line

When we see a dog smile, we can’t assume the dog is feeling ecstatic. If she’s just finished your four-mile marathon training run, she’s probably trying to cool down and catch her breath. She was happy back at mile one. If you’ve taken her to the beach and she’s been splashing around in the waves, she’s probably tired and happy!

Of course, you know your dog best. And in the beaming face of uncertainty, it’s nice to just enjoy that gorgeous smile and give one right back.