There is the classic “pant smile” (a common dog I’m a San Francisco 49ers and a San Francisco Giants for life shirt expression during play–think, tongue out, back teeth showing, mouth open and upturned into a “open” smile while panting with excitement or happiness). In this case, it is undeniable that the dog is in a good mood–not just based on his mouth, but his entire body language. Still, this is not technically a “smile” in the human sense. It does not require the same amount of muscle movement/coordination as a human smile, is not as controlled or complex, and is not used as a primary indicator of the dog’s mood (unlike, his tailor stance, for instance). In fact, open mouth panting can also be a sign of anxiety, hyperactivity/energy, or just being hot. That being said, a clearly happy dog, wearing a clearly happy expression, is certainly using body language to display this happiness in the same way a human uses a smile to display theirs.
I’m a San Francisco 49ers and a San Francisco Giants for life shirt, sweater, hoodie, and ladies tee
Best I’m a San Francisco 49ers and a San Francisco Giants for life shirt
What’s dangerous about misreading this expression as a ” I’m a San Francisco 49ers and a San Francisco Giants for life shirt smile” or even an anxious one, is that the submissive “grin” can be hard to distinguish from a full-on an aggressive snarl. Even if a dog is displaying unease via submissive smiling, squinting, ear flattening, etc…he or she could quickly snap, out of fear or distress. In either of these two above cases, bearing front teeth with a shut, tense jaw, submissive or aggressive stance, and uncomfortable body language are certainly not what we would deem a smile.