Perhaps the most common misinterpretation of dog behavior is based on the myth that a dog wagging his tail is happy and friendly. Although some tail wags are associated with happiness, others can signal fear or even the warning that you are about to be bitten. The tail’s position, specifically the height at which it is held, serves as an emotional meter. If the tail is held at a middle height, the dog is relaxed. As the tail position moves up, it is a sign that the dog is becoming more threatening, with a vertical tail being a clearly dominant signal meaning, “I’m boss around here.” Similarly, barks say a lot about what your dog is thinking. Low-pitched sounds (growls) make the animal seem large and dangerous; they usually indicate anger and the possibility of aggression. High-pitched sounds mean the opposite, a request to be allowed to come closer or a signal from a large dog saying, “It’s safe to approach.”
Sound the alarm A rapid string of two to four barks with pauses between is the most common form of barking. It means, roughly, “There’s something going on that should be checked out.” Continuous barking at a lower pitch and slower suggests the dog senses an imminent problem. It means “Danger is very close. Get ready to defend yourself!”
Hey there One or two sharp, short barks of high or midrange pitch is the most typical greeting sound, and it usually replaces alarm barks when a visitor is recognized as friendly. Many people are greeted in this way when they walk through the door. The message is “Hello!”
Let’s hang out A long string of solitary barks with a deliberate pause after each one is a sign of a lonely dog asking for companionship.
Time for a tussle A stutter bark, which sounds something like “harr-ruff” is usually given with front legs flat on the ground and the rear held high. It means, simply, “Let’s play!”
Salutation A slight tail wag, each swing small, is usually seen during greetings and can be interpreted as a tentative “Hello there” or a hopeful “I’m here.”
Satisfaction A broad tail wag is a friendly “I’m not challenging or threatening you.” In many contexts it may also mean “I’m pleased,” and it is the closest thing to the popular conception of the “happiness” wag, especially if the tail seems to drag the dog’s hips.
Confusion A slow wag with tail at “half mast” is less social than most of the other tail signals. Slow wags with the tail in neither a particularly dominant (high) nor submissive (low) position signal insecurity or uncertainty about what to do next.
Fight or flight Small, high-speed tail movements that give the impression of vibrating are a sign that the dog is about to take action (run or fight, usually). If the tail is held high and vibrating, it signals what is most likely an active threat.
Reprinted from Do Dogs Dream?: Nearly Everything Your Dog Wants You to Know by Stanley Coren. Copyright © by Stanley Coren. With the permission of the publisher, W.W. Norton & Company, Inc. This selection may not be reproduced, stored in a retrieval system, or transmitted in any form by any means without the prior written permission of the publisher.