Why Does My Dog Show Their Teeth?

February 20, 2023

By: Kristyn Savage, PhD, CAAB, BCBA-D
Why do dogs show their teeth

Most of the time, we think of a warning behavior when dogs show their teeth. It generally serves as a precursor for more aggressive behavior. It is a warning to back away or stop what you are doing. There are, however, times when dogs show their teeth for a much different reason and one that, as a Certified Applied Animal Behaviorist, is one of my favorite dog behaviors. This behavior often leaves owners alarmed or confused. It involves showing teeth as a sweet appeasement gesture and is referred to as a submissive grin! 

How do submissive grins and warnings look different?  

Dog showing teeth - submissive grin

When dogs show their teeth in a submissive grin, they primarily show their front teeth. The same goes for a warning that the front teeth are primarily shown. This makes it difficult to tell the difference if we only have the dog’s mouth to guide our judgment. Luckily, if we are observant, dogs communicate loud and clear with other corollary body postures. 

The other correlated body postures suggest friendly behavior when dogs engage in submissive grins. These other postures might include a low tail wag, ears pulled back, and squinty eyes. Their whole body seems to wriggle with happiness. Conversely, when dogs show their teeth as a warning, correlated body postures might include a stiff body, direct, hard eye contact, or a whale eye, and either tucked or very erect tail posture. These additional body postures make it easier to determine the intent behind a dog showing their teeth.

Looking at the environment to help determine whether a grin is a warning or submissive

The environment — in other words, the context in which the behavior occurs — can help give a clearer picture of intent. We can make reliable estimates about why a dog is showing their teeth by considering the environment. 

When dogs offer a submissive grin, they are usually the ones doing the approaching. Submissive grins are displayed during greetings, often when you’ve been separated from your dog or with new guests or playmates for the overly friendly canine. The submissive grin occurs within the first few seconds of greeting rather than after a long period of engagement.

Conversely, when dogs show their teeth as a warning, the target initiates the interaction. Common contexts include anything related to restraint, confinement, or a valued resource. 

Imagine a well-intended groomer giving Fido a monthly nail trim or a guest reaching down to pet the dog who has their favorite new bone. The context can include more typical occurrences that are simply painful, scary, or uncomfortable. A toddler might crawl over and use the dog as a makeshift jungle gym. Sometimes even periods of cuddling can change for seemingly unknown reasons, and dogs will begin showing their teeth while being petted. The same could easily be imagined by a young puppy approaching an older dog happily, with the older dog warning to say, “leave me alone.” Sometimes, a greeting or other engagement has gone on too long. During a snuggle session, a loving owner pets their dog for a bit too long, or a tolerant older dog is pestered one too many times by their younger counterpart. In all these contexts, the human or dog approaches the dog giving the warning, and sometimes but not always immediately preceding the warning. 

Dog in the crate showing teeth - submissive grin

Where did submissive grins originate?

Others speculate that, like many other dog-specific behaviors and body postures, there is likely an evolutionary benefit. More submissive pack members greeted and licked the faces of more alpha members. That fast licking was coupled with the submissive grin exposing portions of the dog’s mouth. Those dogs that engaged in submissive grinning passed it off to their offspring, hence the current submissive grin. I can offer only speculation and am admittedly not an evolutionary biologist. I recommend other reputable sources for more information on the origination of the submissive grin. The Animal Behavior Society‘s website is excellent for looking for those sources.

Using the guidelines above, you can feel confident in knowing the intent behind a dog showing their teeth. If your dog engages in submissive grinning, consider yourself lucky! Those sweet smiles are hard to come by in our modern dog. Stay tuned for my next blog, which will cover a less desirable appeasement gesture — submissive urination!