HBO's adaptation of Naughty Dog's famed Left Behind DLC is a heartbreaker ...

Dogs smile by pulling one or both lips back and may show all or some teeth. The "smiling" is often accompanied by other greeting behavior s, like approaching, wagging or even whining.

Any dog can smile, and according to veterinary behavior specialist Dr. Lore Haug, some breeds are even genetically predisposed to smile more than others (Doberman Pinschers, terriers and cattle ...

I am not aware of other animals that smile in the way that dogs do. And I think again, that's partly because the dog smile, as I mentioned in the article, is a specifically people directed behavior.

This is a sign that the dog is content and relaxed. It is the closest canine equivalent to a human smile. You can see it in virtually all breeds of dogs such as those depicted here.

Dogs smile by pulling one or both lips back and may show all or some teeth. The "smiling" is often accompanied by other greeting behavior s, like approaching, wagging or even whining.

Dogs smile by pulling one or both lips back and may show all or some teeth. This smiling is accompanied by other greeting behavior, like approaching, wagging or even whining.

This is a sign that the dog is content and relaxed. It is the closest canine equivalent to a human smile. You can see it in virtually all breeds of dogs such as those depicted here.