Dogs use a lot of different physical methods and gestures for indicating their feelings and attitudes toward us. Some are complicated, while others are readily apparent. There are the vocal cues, of course, that can indicate a dog’s internal condition to us. But a dog’s physical gestures can communicate a lot without even a whine, bark or yelp. Body language can be conveyed through facial expression, tail and ear positions, and in the way the dog holds its body. Successfully reading a dog requires your full attention of all of these elements simultaneously.
When a dog is relaxed and peaceful, it will generally hold its ears a little bit back but up, the head will remain high, and the tail hangs loosely in a downward curve. The front and back positions of the body are balanced and at the same level, the musculature between the forehead and muzzle smooth and unruffled. A relaxed dog will also keep its mouth slightly open with the tongue hanging out, perhaps panting lightly, with clear eyes.
When a dog becomes more alert, the ears point upward or lift slightly in a forward manner (such as with long-eared dogs), and the tail is raised and wagging slightly. The dog may cock its head to indicate curiosity and minor creases will appear on the forehead as it focuses its vision and hearing on the activity at hand. Some dogs may bring one of their front legs up slightly, as though they are ready for whatever is coming their way.
If the dog senses an opportunity to play, it will lower its front body into a “ready, set, go” position, with elbows and chest almost touching the ground and the back end raised up, tail wagging enthusiastically. The ears are alert, pointing up or forward, the mouth open but relaxed. The dog may bark enthusiastically as he or she invites a playmate to join. These are all healthy signs of a lively dog that is able to communicate with joy and enthusiasm.
Conversely, when a dog feels threatened its body language changes. The response may depend on the dog’s personality as well as its perception of the possible threat. A confident and dominant dog will take on an aggressive posture when it perceives the onset of a threat. The ears are upright and forward, the mouth slightly open with the upper lips curled to expose the threatening canine teeth. The facial musculature will change as wrinkles appear around the forehead and nose as the dog opens its eyes wide to take in as much of the visual surrounding as possible. The tail will be raised, not lowered, to signify that the dog is taking a dominant posture. The tail may be kept stiff, or the dog may wag the tip of its tail in quick circles -- much different from a friendly, relaxed wag.
The dominant dog will stand with its neck and body erect, with its hackles raised to give it an inflated look, comparable to the way a man will inflate his chest when demonstrating his masculinity. Some dogs will stiffen their legs so much that they are virtually on tiptoes. The total posture of the dog under threat is meant to convey size, strength, power and boldness, all directed at the intruder.
The signals can change drastically if the dog feels that it is outsized or if it is being met with a situation it does not know how to respond to. A dog that is suspicious or fearful will lower its head into a submissive position, flatten its ears and tuck its tail between its back legs. The mouth may be open in a scowl with curled lips, the eyes glazed and averted away from threat. The hackles will be raised even as the body is lowered body and it retreats from the source of fear. This is the fear-biter posture. The dog is retreating from the threat, but it will defend itself if attacked.
These physical gestures are both aggressive and submissive and can be confusing to an observer who is not familiar with the body language of dogs. It is not a good idea to approach a dog that is exhibiting these behaviors.