It is a common misconception that a dog with a wagging tail is a happy, friendly dog. In reality, a tail wag can be meant to communicate a variety of things, including fear and aggression. As a general rule, humans aren't the best at interpreting a dog's body language, and all too often this leads to negative situations. The key to avoiding dog bites, and improving your relationship with your dog, is to understand what they're trying to tell you!

Tail Direction

Let's start with the tail. Did you know that you can tell if a dog feels positively or negatively about an item or person, by the way they wag their tail? A dog who wags their tail more to the right side feels generally positive about someone or something at hand, where as a dog who wags their tail more the left feels negative about it. 

Friendly Tails

The dog's tail position, movement speed, and tail stiffness all communicate a great deal about the dog's mood. For example, a relaxed, happy dog will have a tail that is loosely wagging and will hold the tail at body level (unless the dog breed has a tail with a naturally high curl). This dog is calm and is in the proper mood to greet strangers or children.

A dog who is extremely excited to see a specific person will sometimes do what we call a "propeller wag", where the tail goes in a full circle. If you are lucky enough to be on the receiving end of this wag, you know you're an extremely special person in the eyes of this dog. 

A dog whose whole body is wiggling and wagging is extremely excited and happy, but should calm down before interacting with children. Still, this is a happy, friendly dog.

Unfriendly Tails

If a dog's tail is held high above it's body and is either still or moving stiffly, this is a warning: back off. It is important to note that some dogs have tails that naturally curl above their bodies, so it's particularly important to note the tails movement in those cases. You should not approach a dog in this state, they are busy assessing what is going on to determine their next move.

Another clue that a dog is deciding what to think about a situation: slow tail wag and stiff body. Again, back off.

If a dogs tail is held high and either bristling, vibrating or wagging quickly and stiffly is a dog that might be ready to attack or bite. Avoid this dog.

Unsure or Fearful Tails

A dog whose tail is tucked tightly between its legs is scared and fearful. Fear can turn into submission or aggression, so it's best to give this dog space.

Learn More

Curious about overall dog body language? Look at this great peice put out by the ASPCA!

Learn more about a dog's tali (including video and photos) here.