The staff at McFarland Orthodontics is made up of almost 100% dog lovers. Almost all of us have a cute canine to call our own... Just ask Dr. McFarland about his beloved dog Boo, for example, and watch his face light up. He is a rescued white boxer with a sweet, slightly-mischievous personality. As smile professionals, we were curious to know about our dogs' smiles. Do they smile like their humans do? Or do they show happiness in another way?

We've experienced the exuberance that a happy dog displays when we walk through the door, ask if they want a treat or take them on a walk. But are we projecting our human expressions onto our pups so that we see them as smiling—or are they smiling for real?

Victoria Schade, author of the book “Bonding With Your Dog,” says, “Dogs use their bodies to express happiness in many ways, but a true human-style smile isn’t normally one of them.” Schade summarizes that we’re looking at happy dogs engaged in activities they enjoy, like playing or running, and translating their wide, panting mouths into smiles. She adds, “The canine equivalent of a smile is a bouncy body, a loose tail wag, and a facial expression with soft eyes and a relaxed mouth and ears.”

Kim Brophey, certified canine behavior consultant at Dog Door Behavior Center, TEDx speaker and author of “Meet Your Dog,” sees dogs “smiling” as an adaptive facial expression and behavior with a range of evolutionary functions and benefits. Highlighting a communication correlation, she says, “What we view as ‘smiling’ can serve to mediate conflicts, communicate deference and facilitate bonding.” Brophey notes that dogs naturally appear to employ adaptive “smiling” behaviors as a social skill and expression of emotion. She adds, “Though it’s fun to think about dogs as smiling deliberately, the reality is that there are very complex evolutionary forces at work.”

As to why we react the way we do when we see a dog “smiling,” Brophey says it’s a combination of oxytocin and evolution. “Dogs are masters at human behavior observation and manipulation,” she says. “That’s their niche. Their ancestry and experiences have informed them on how to be effectively charming.”

This “smiling” is endorsed by humans when they react, laugh, give treats, pet and clap. Dogs quickly learn that this is a positive reaction to their behavior and will continue to smile because of it.

Brophey understands this on a scientific level, but gleefully admits that she is duped on a daily basis by the dozens of dogs she meets. She does, however, remind herself and others to honor and respect the evolutionary love story between people and dogs. Each and every dog is a complex biological individual with their own emotions, intelligence, experience, personality and opinions.

So there you have it... Dogs show happiness in their own unique ways that differ from a human-like smile. But we still reserve the right to be tricked by our dogs' silly "smiles" when they greet us merrily at the door.