It is quite common for me to see dogs of all sizes and ages give a big yawn when they are in for their physical examination or vaccinations. People often laugh and think their dog is sleepy or bored but the truth is they are unfamiliar with dog language.
People have a variety of facial expressions to help transmit how they feel but dogs lack a lot of the facial muscles people have. Dog communication is quite different from people and yet they have a similar 'pack' mentality so they adjust well to living with people.
The problem comes when a subordinate dog is put in an unfamiliar setting and placed in a stressful situation. Some dogs will lash out aggressively, others will sudden strike out; the so-called 'fear-biters.' Other dogs will act very submissively and urinate, look away, roll over or in other cases yawn. The yawn helps a dog prepare for a stressful situation by revving them up or calming themselves down.
Just as in people yawning is contagious and if you catch your dog's attention when you yawn you often will see them yawn. Try it - maybe you both will relax a bit.
