Depending on the context and your dog's overall body language, your dog's "smile" can be interpreted several ways tied to his emotions or state of being.  The next time your pup smiles at you, it could mean he is one or more of the below. I imagine my dog admires me when he smiles … or he is buttering me up for some treats. Eh, halfers.

• Relaxed, calm, and happy - slightly open mouth and visible teeth

• Panting - cooling, comfortable and maybe excited

• Playfulness - wide-open mouth with tongue hanging out

• Submission - lips pulled back to show front teeth

• Bonding - relaxed and comfortable happy expression

• Mirror you - mimic you and get positive affirmation