Yawning is a cross species action.  People yawn, dogs yawn, cats yawn, monkeys yawn and some reptiles yawn.  With people, yawning often signifies fatigue or disinterest so we have personified the yawn to indicate that our pets are tired.  Canine behaviorists now believe that there is more to a dog yawn than a tired dog.

There is a joke within human circles that if you see someone yawn, you will catch it.  While yawning isn't exactly contagious, there is a social modelling theory that suggests that a yawn is a social cue that you will replicate subconsciously to connect with that individual.  When one person yawns, those watching will begin to yawn.

Canine behavior experts believe that yawning plays a role in canine social behavior as a calming signal.  Yawning is just one calming signal that dogs use to signal stress or discomfort and to diffuse a situation.  Often when two dogs are meeting for the first time, one dog will signal to the other that they are not a threat or threatened by yawning.  Dog owners are often shocked when they take their dog to an event with lots of people, noise and scents that the dog will sit back and let out a yawn.  The pooch is not tired or bored, but is signalling that he/she is uncomfortable. 

The next time your dog looks stressed (at the vet, at the groomer, going for a car ride, etc.), get his/her attention and yawn in an exaggerated manner.  Maybe your pooch will reply with additional calming signals or simply relax. 

Learning to recognize stress signals in your dog as well as dogs that you may interact with is key to guiding the interactions to a positive end.  Observe your pooch as you meet new people, visit new locations and take note of any yawning.  You will be able to learn a great deal about what makes your dog uncomfortable and how he/she interacts with others.