Dogs can communicate with other dogs through a series of signals, including a variety of facial expressions, body postures, noises, and scents. Your dog will use his mouth, eyes, ears, and even his tail to express his emotions. By reading the combination of body signals, you should be able to work out who is top dog in any confrontation or situation.
A dog that feels brave or aggressive will try to give the impression of being a larger, more powerful animal. He will stand tall with his ears and tail erect and thrust his chest forward. He may also raise the hairs around his neck and along his back (his hackles). Aggressive dogs may also wave their tail slowly and growl.
A submissive dog, on the other hand, will try to appear small and puppy-like. Adult dogs will chastise puppies, but they don't attack them. A submissive dog's approach to a more dominant canine or human is likely to be from the side, crouching near to the ground with his tail held low and wagging enthusiastically. He may also try to lick the hands or paws and face of the dominant dog or person. If this isn't appeasing enough, he might then roll onto his back to expose his stomach, or even involuntarily pass a small amount of urine.
The many meanings of tail wagging
One pattern of behavior that's characteristic of dogs and familiar to almost everyone is tail wagging. Most people recognize that loose, free tail wagging indicates pleasure or friendliness. Exaggerated tail wagging, which extends to the entire rump, is sometimes seen in subordinate dogs, as well as dogs with very short tails.
The tail, however, is also an indicator of other emotions. A tail waved slowly and stiffly, in line with the back, expresses anger. Clamped low over the dog's hindquarters, it's a sign that the dog is afraid. Anxious or nervous dogs may stiffly wag their drooping tails as a sign of appeasement.
Facial expressions—and more
The facial expressions of your dog will tell you a lot about his mood—whether he's anxious or excited, frightened or playful, or any one of a vast range of emotions he may express. His ears prick up when he's alert or listening intently, but are held back or flattened onto the head when expressing pleasure, submission, or fear.
To successfully read his mood correctly, you must watch for other body signals at the same time. The narrowing or half-closure of the dog's eyes indicates either pleasure or submission, but when his eyes are wide open, he's signaling aggression.
Eye contact: Who blinks first
In the wild, the pack leader can maintain control simply by staring at a subordinate dog. The two animals will continue to stare at each other until one challenges the other, or until one lowers his head and turns away. If the staring continues after the submissive dog has looked away, he will feel confused and may bite out of fear. If eye contact is not broken, the dominant dog will reinforce his threat by snarling, growling, or even attacking.
You should not try to outstare your dog if he has aggressive or nervous tendencies because this could provoke an attack. Nevertheless, regular, gentle eye contact reassures the dog and reinforces your relationship.
Smile, we're communicating
Submissive dogs may appear to be "smiling" when they open their mouth to show their teeth in a lop-sided grin of friendliness. In the snarl of aggression, however, both lips are drawn right back to expose most of the teeth, and may be accompanied by a growl.
A dog will indicate his desire to play by raising a front paw, or by performing the play bow, which is often accompanied by barking to attract attention. Other gestures include offering a play object or bounding up to another dog to invite a fun and friendly chase.