Yawning Doesn't Always Mean Your Dog Is Tired
Several canine behavior experts believe yawning plays a similar role in canine social behavior. Recently I saw dogs playing at a local dog park use yawning behavior to slow down a really rough play session. Several large dogs were running around the dog park, with a few small terriers in pursuit. When the terriers caught up with the big dogs, they began nipping at legs, jumping at faces, and otherwise showing some really rough play. In the middle of the rough play, two of the larger dogs sat down, scratched, and yawned. After these two dogs yawned, a third and fourth yawned, and the activity level of the play slowed significantly. A potential dog fight was averted -- all because a few of the dogs scratched and yawned!
Recently I was teaching Riker, my four-year-old Australian Shepherd, a new scenting exercise in which he had to find a scented article hid among other articles with different scents. (This is similar to the AKC scent discrimination exercise in Utility-level obedience.) I thought the training was progressing well, but then I noticed Riker was yawning at me. He would make eye contact, hold it for a second, look away and then yawn. He was trying to tell me to ease up a bit. We did something else (a few easy retrieves) so I could stop his training session with praise for him, and then took a break from our training for a few minutes. I let him run, relieve himself, I rubbed his tummy, and then we went back to training. With that break, he was back on course and our training session ended well.
Although some experts have suggested that dog owners can use yawning to change their dog's behavior (for example, to calm a tense situation), I have not seen that to be very effective. For a human yawn to change canine behavior would require the dog to be willing to accept that kind of guidance -- and if the dog were willing -- other training tools or techniques would work just as well.
However, knowing that your dog may yawn to calm you or to relieve stress you may be putting on the dog (especially in training situations) can be very useful. Just recognize that a yawn may signal more than sleepiness!