Because animals have no language abilities like humans do, they use their bodies to communicate, including their ear positions, eye contact and their tails.
Direct eye contact with whoever the dog is facing may be the dog’s way of saying back off or flat ears may indicate fear or even aggression. But it’s the dog’s tail that is the most expressive. When owners dock a dog’s tail or ears, they are limiting that animal’s ability to express his feelings.
We humans are prone to thinking that when we see a dog wagging his tail, that this is a sign of friendliness, but this is not necessarily the case. You have to look at the tail’s position to figure out what the dog is communicating: a raised tail or tail moving up means “I’m top dog here and I’m running the show.” A tail that is moving down is saying “You’re top dog here and you are running the show.”
And a tail that is tucked between the dog’s hind legs is saying “Hey I don’t mean any harm. I’m not going to hurt anyone and please don’t hurt me.” This is a clear sign of submission.
If the dog is wagging his tail (moving it side to side) we always tend to think this is a happy dog but you have to look at two factors here: how fast is the tail moving and is the dog wagging his tail more to the left or to the right.
Let’s look at direction first. You may know from biology class that in humans as well as animals, the right side of the brain controls the left side of the body. In humans as well as dogs, the left side of the brain is associated with positive emotion and the right side with negative emotion.
So, if the dog’s tail is moving back and forth but shows more movement to his right, then the dog is most likely exhibiting positive emotion. In dogs, these positive emotions are interest or excitement. But if the dog’s tail is moving more strongly to the left, then the dog is showing more negative emotion, such as fear, aggression or anxiety.
The final factor to consider is speed. The faster the tail is moving the more intense the emotional signal. But in general, if the tail is wagging very slowly this is a signal the dog is calm and can most likely be approached. So now you know the language of the tail.
Observe your dog and other’s dogs and notice the differences in tail position. You can learn a lot just by looking!