Why Do Dogs Show Their Teeth?

Medically Reviewed by Vanesa Farmer, DVM on July 14, 2023
4 min read

Since dogs can’t talk, they communicate with us through facial expressions, posturing, and body language. The more you learn to understand what your dog is saying by reading their body language, the better you can respond to their needs. One way that dogs show their feelings is by showing their teeth or pulling back their lips so that their teeth are displayed.

There are many different reasons why your dog may decide to bare its teeth. Part of being a good dog owner is understanding the body language your dog displays in different situations. The benign reasons that your dog may show its teeth include:

Showing submission. Your dog may show its teeth when smiling at you while letting you know it accepts that you're the leader. It’s a sign of respect, not of aggression. You can typically tell the difference by looking at your dog’s posture. If it is relaxed, then there’s nothing for you to worry about.  

Showing friendliness. Dogs will also show their teeth at other dogs or humans as a way of extending friendship. They want to let them know they’re not interested in fighting. 

Playing around. When your dog plays with you or with other dogs, it may have its mouth open and its teeth bared. Pay attention to other signs that your dog is in play mode, such as light sneezes, a low posture with a raised rear, pricked ears, or a wagging tail.

The energy given off by dogs showing their teeth for non-threatening reasons tends to be very different than when they do it as a sign of aggression. Situations where your dog may be prompted to bare its teeth as a warning include:

Not liking the restriction of a leash. Dogs can respond in an aggressive manner when they are on a leash. They typically greet other dogs by approaching them from the side. A leash can make this difficult and force them to perform a head-on greeting. They may show their teeth and display other behaviors like growling, lunging, and jumping to get away from the threat. Being on a leash can also prevent your dog from getting distance from another, leading to more belligerent body language. 

Social aggression toward other dogs in the home. The leadership hierarchy can often change when there are multiple dogs in a household. Context can also come into play. Your dog may show deferential treatment to other dogs in some situations, like who gets to the water bowl first, but show their teeth in other scenarios, like who gets to play with a dog toy. 

Responding to pain. When dogs are in pain, they may show their teeth as a way of protecting the injury. They may do this to you and even follow it up with a bite to defend themselves from new threats. Approach your dog cautiously if you believe it is nursing an injury. Avoid using any training device that can hurt your dog, like an electric collar, shock collar, or choke chain. Your dog may become more aggressive to avoid the pain these devices cause. 

Guarding something important to them. Dogs can be territorial creatures. Mother dogs may show their teeth to others if they feel they pose a threat to their puppies. Your dog may feel driven to guard the home and bare its teeth to anyone who sets foot on the property, including the mailman, deliveryman, and even passersby. Some dogs are genetically predisposed to displaying hostile behavior to even the slightest perceived danger. 

Trained to behave that way. Many dogs end up in shelters because of abusive behavior from previous owners. They may have trained their dog to bare their teeth and growl, to act aggressively toward strangers, to guard the house against intruders, and to mistrust anyone who isn't the owner. 

Fearful of a threat. Dogs who feel their safety is at risk may show their teeth to try and make the danger go away. This behavior is reinforced if the threat does actually leave, such as when the mailman goes back to his truck, The dog will believe its actions caused the threat to disappear. Dogs may view a gesture as threatening or they may associate someone's presence with danger, and they'll act aggressively out of fear. 

Your response to a dog showing its teeth should depend on the situation. If the dog has issues going out on a leash, try keeping it away from other dogs. When another dog appears in the distance, distract your dog by getting their attention, then rewarding them. That helps them learn not to view other dogs being in their space as negative or dangerous.

If your dog consistently shows its teeth or shows other aggressive behavior in the home, look at what you can do to adjust their environment. Remove anything they might perceive as threatening. Keep in mind that dogs who show hostile behavior toward other family members are not necessarily doing it to establish dominance. They may be afraid of something, and that anxiety can cause them to react in an antagonistic manner. 

Show Sources


Tufts University Center for Shelter Dogs: “Dog Communication and Body Language.”

Michelson Found Animals: “What is Submissive Dog Smiling?”

American Kennel Club: “How to Read Dog Body Language.”

VCA Hospitals: “Canine Communication: Interpreting Dog Language.”, “Dog Behavior Problems – Aggression to Family Members – Introduction and Safety.”

Animal Humane Society: “Aggression in dogs.”

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