I often hear the misconception that a wagging tail = a happy dog. This can get people into a lot of trouble and cause unnecessary stress to our dogs.
A slightly lowered tail with the end wagging quickly is likely to indicate a dog is anxious. A wagging tail raised high in the air is likely to mean the dog is aroused and this may be due to a positive or negative emotion.
The key is looking at the dog's whole body language and not just the tail. A good example of this is watching the first 35 seconds of this clip. This dog is clearly worried but his tail is wagging!
Look for the dog turning his head away, leaning away, lip licking, yawning and licking the man. His whole body, including his ears and muzzle are tense and he is trying to move away. Very uncomfortable viewing.
In order for us to create better relationships with our dogs, education is needed. For more information on talks, recommended reading or a visit to help you understand your dog(s), please do not hesitate to contact me.