Why Do Dogs Wag Their Tails?


Most people know that a dog's tail is one of their main forms of communication. A happy dog has a wagging tail, right? Unfortunately this isn't the case. Just like a smiling human isn’t always a happy human, a waggly tail can mean a whole lot of different things.

A dog's tail helps to balance it while running, but it also gives a valuable insight into their emotional state. In general, a wagging tail means a dog is interested in having an interaction. It also means the dog is excited by the situation, and the faster the tail moves the more excited they are.

New research also shows that the side that the tail wags on indicates a dog's emotional state.  Wagging on the right side indicates a positive emotion, and on the left side a negative emotion. The researchers think that this is a result of the way the left/right hemisphere’s of the brain control their bodies.

In order to get a better understanding of your dogs wag, there are 4 things to look for.


  1. Height: Whether a tail is heard up or down can often indicate a dogs level of assertiveness. A low held tail submissive, but a high held tail can mean that a dog is feeling dominant. Use caution when approaching a dog with a tail held over it’s back, it could be aggressive.
  2. Stiffness: A loose, relaxed tail tends to mean a happy relaxed dog. A firm, stiff tail can be a sign of agitation.
  3. Side: Wagging on the right side indicates a positive emotional state. The left side is correlated to negative emotions and should be approached with caution.
  4. Speed: How fast a tail moves indicates the amount of energy the dog has. Read in combination with these other factors it can tell you the level of intensity. So for example a fast moving, low held tail most likely belongs to a dog that is feeling very submissive. 



The rest of a dog's body language will give further clues as to a their emotional state as well. Pay particular attention to eye contact and ear position. Intense eye contact and raised ears can be a sign of aggression. Eye avoidance and dropped ears is a form of submission.

It’s important to note that all dogs are different, and they use their tails differently too. So don’t assume you immediately understand a new dogs tail movements!

Take the time to establish rapport with every dog you meet and you will be rewarded with a deeper connection to our doggy friends.