dog, wag, tail

Why Do Dogs Wag Their Tail?

There is something quite warming when you get greeted by your dog at the front door, and you see their tail wagging a hundred miles an hour, signaling to you that they are so incredibly happy you are home. Maybe you noticed their speedy tail when you ask them to go for a walk, feed them their favorite treat, or ask them to go for a ride. Because you are likely to have noticed this quite adorable feature about them, you may have associated tail wagging with them being happy. Though yes, this can certainly be the case at different times, the reality is that this tail-wagging motion goes much deeper than that. In fact, it can indicate the exact opposite of them being happy. 

Dog Tails

In an evolutionary light, a dog’s tail was primarily there for balance. It helped/helps them make sharp turns, climb hills, and stay steady when running. But as time went on, it became less about balance and more about communication.

Did you know that dogs are not born wagging their tails? Tail wagging typically shows up about a month into their life when the puppies begin learning how to communicate with each other. They may start wagging to request things like milk or food from their mother or to signal their brothers and sisters that they are being too rough and need to back off. And this continues well into their adult life. 

What Your Dog’s Tail Is Telling You

“It is so important for people to realize that a wagging tail does not equal a dog that is friendly or wants to be petted.” – E’Lise Christensen Bell, a board-certified veterinary behaviorist at Veterinary Behavior Consultations in NYC.

Now, it might sound strange, especially if you are unfamiliar with dog body language, but tail wagging does not always mean that a dog is happy. It can certainly be the case of excitement or happiness, but the way in which a dog wags their tail can help you pinpoint what message they are trying to convey, such as agitation, anger, and annoyance. 

  • Direction: To help you figure out what a tail wag means, check out the direction it is swaying. Studies have shown that dogs who wag their tails leaning towards the right are happy, and are scared when wagging on the left. For puppies, if they wag their tail high and side to side, that means they are happy. If lowered, they could be feeling worried or insecure, and tugged in between their legs means they are probably frightened or being submissive. 
  • Speed: The tail wagging speed plays a vital role in figuring out a dog’s social cues as well. For instance, a broad/light wag means the dog is being friendly and not challenging, whereasa half-mast slow wag means they are less social, either more dominant (high) or submissive (low). In addition, if you see high-speed, tiny movements, the dog is likely about to either run or fight. 
  • Non-Mood Related Circumstances: Sometimes, dogs wag their tails not to express emotion at all. They could often use their tail to spread their unique, natural scent to establish their dominance. For reference here, if a dog is trying to release their scent efficiently, they will wag with their tail up in the air, as the tail down will make it hard for their scent to travel. If a dog is scared to release their scent for some reason, they will tuck their tail between their legs, trying to contain their smell to essentially “fly under the radar.”
  • Communication with Other Dogs: Tail wagging is also an excellent way for dogs to communicate with each other.Dogs can use their tails to let other dogs know to stay away or that it is safe for them to approach. It remediates any miscommunication between the two of them, significantly reducing the risk of fighting. Keep in mind that tailless pups have a hard time interpreting tail wagging cues such as this, so you might discover they tend to get into challenging conflicts more often.


Though dogs might seem like pretty simple animals, which they are to a degree, their tails are one of the more complex parts about them. Depending on the location, speed, and situation your dog is in can all dictate what their wagging tail is trying to say. So, to answer your question on why dogs wag their tail, pay attention to the situation your dog is in when and the distinct motion of their tail they are performing. By being more mindful in this sense, you should be able to pinpoint what your dog is feeling and have a much better connection with them than ever before.