Why do dogs wag their tails?

One of the most common myths about dog behavior is that a dog that wags its tail is a happy and friendly dog.

The reality is much more complex.

While some stirrings are indeed associated with happiness, others can mean fear, insecurity , or even a warning before an attack.

Each wagging tail actually emits its own social signal, varying from situation to situation.

The good news is that you can decipher this signal by observing the position of a wagging tail, its speed, and the range of its movement.

Want to understand the messages your dog is sending you? Find out how to read Its tail movements.

My dog ​​wags Its tail: a way of communicating like any other

In a way,  a dog wagging Its tail serves the same communication functions as a human smile, a polite greeting, or a token of recognition.

when a human displays a smile, does that mean they are happy? Not necessarily!

It can mean “Hello”, “I am coming as a friend”, “Thank you” … And a multitude of other things.

Smiles are complex social signals with infinite meanings and nuances.

They are also reserved for situations in which someone is present to see them.

It is the same for dogs.

Besides the fact that dogs wag their tails to express a wide variety of feelings, they also wag their tails only when other living things are present to receive the message – a person, another dog, a cat, a horse, etc. even an object with a living appearance.

In other words, a dog alone will not wag its tail, just like humans do not smile for walls.

Wagging the tail is an effective way of communicating, as sight is an extremely important sense for our dogs.

And in the absence of verbal vocabulary, dogs communicate broader messages through body language by adopting a certain position, moving their ears, frowning, moving their eyes, or wagging their tails.

The evolution also helped make the tail more visible. Some tails have color variations such as dark or light ends, others are lighter on the underside, and still, others are very bushy.

All of these traits accentuate the flapping of the tail and improve communication.

However, canine communication through the tail is not entirely innate.

And since human babies must learn to speak, dogs must learn their language.

It is when puppies are about a month or so that they begin to understand the need to communicate with their mother as well as siblings.

They learn the lingo and start wagging their tails to tell littermates that they are tired of playing or to tell their mother that they are hungry.

My dog ​​wags Its tail: The different dialects

Before learning to speak “tail wagging”, it is essential to clarify that the neutral or natural position of a dog’s tail varies according to the breed.

Most dogs have a tail that hangs down at their heels when relaxed. But some dogs, like Beagles, hold their tails more vertically.

Others, like Greyhounds, place their tails under their bellies.

Still others, such as Pugs and Boston Terriers, have tails that curl tightly around the body and wag little.

Just as there are different dialects in humans, there are also dialects in the dog tail language.

Thus, all positions and movements should be read relative to the average position where the dog normally holds its tail.

Why do dogs wag their tails?

My dog ​​wags Its tail: what does It mean?

The position of the tail, its orientation as well as its movement and amplitude, are all clues that can help you decipher the message your dog is trying to convey when It wags Its tail.

The position of the tail

The position of the tail, and more precisely the height at which it is held, can be seen as a kind of emotional meter.

An average height suggests that the dog is relaxed.

The higher the tail position, the more threatening the dog becomes, with a vertical tail being a clearly dominant signal: “I’m the boss here”, or a warning, “Back off or suffer the consequences”.

Agitation or increased attention

If the tail is held horizontally, it means that your dog is particularly receptive to Its surroundings.

When dogs are on alert, they stand upright with their ears raised and their tails up and outstretched. This posture indicates that they are attentive and ready to face anything that catches their attention.


When a dog suddenly stops wagging Its tail and freezes, leaving it in a natural position, it may mean It wants to deflect a threat without being aggressive.

Many dogs do this when being petted by strangers, to make them understand that they don’t want to interact with them, or in any case that they are not quite comfortable, without being aggressive.


When your dog’s tail shifts from a neutral position to an upright position or curls over its back, it may indicate that your pet is entering an aggressive state.

The higher the tail, the greater the threat.

This high position of the tail also releases more odor from the anal glands. These olfactory signals are a way of marking a territory and signaling its presence to predators and enemies.


If your dog’s tail shifts from a neutral position to a lower position, your companion is likely entering a state of submission and trying to convey that It’s not a threat.

The extreme expression is the tail tucked under the body, which says something like, “Please don’t hurt me”.


If your dog’s tail is snug between Its hind legs, your dog is probably afraid of something, worried, or uncomfortable. It sees a threat and sends the message that It doesn’t want to be hurt.

Unlike a dominant position, this lower position of the tail here reduces the amount of odor emitted by the anal glands and allows the dog to remain more discreet, or even go unnoticed.


When a dog is happy, it holds its tail in a neutral or slightly raised position and wags its tail in a relaxed motion.

The speed at which the tail moves gives extra meaning to canine communication.

Tail speed

Speed ​​gives signals additional meaning.

Movement is indeed a very important aspect of the signal.

Dogs eyes are much more sensitive to movement than to detail or color, so a moving tail is highly visible to other dogs.

The speed of movement indicates how excited the dog is.

Likewise, the width of each tail sweep reveals whether the dog’s emotional state is positive or negative, regardless of arousal level.

Therefore, there are many combinations, including the following common tail movements:


The tail wag can be very slow or extremely fast. The faster the movement, the more excited the dog is.

Sometimes the dog’s tail wags so quickly that it seems to vibrate.


Usually, a dog who is reluctant to meet a new person or another dog wags its tail so lightly that it indicates that it is unsure of itself.

A slow wag with the tail hanging down is less social than most other tail signals. In general, slow wagging with the tail that is neither particularly dominant (high) nor submissive (low) are signs of insecurity.


A very friendly dog ​​can wag its tail more freely and even wiggle Its hips at the same time.

A dog that wags its tail in a broad motion is friendly: “I do not challenge you or threaten you”.

It can simply mean: “I am happy”.

Why do dogs wag their tails?


When a dog wags its tail very quickly while holding it upright, it may perceive an imminent threat and therefore prepare to attack.

So, keep in mind that a person can be bitten by a dog wagging its tail!

The salutation

A slight stir, with a movement of low amplitude, is generally perceived during greetings as a “Hello” or “I am here”.


Small, quick movements that make the tail appear to be vibrating are a sign the dog is about to do something, usually, run or fight.

Unlike the excitement, it is here in the high position while it vibrates. If your dog wags Its tail like this, It most likely senses an imminent threat and may become aggressive. So stay alert!

The tail wag side

Science always discovers new elements that allow us to interpret the behavior of dogs, or reinterpret behaviors that we thought we understood like the meaning of a dog’s tail wagging.

So far, scientists have focused on two main sources of information, namely the tail movement pattern and its position.

However, new data adds an important third dimension to understanding dog tail language.

The dog’s “tail language” is indeed so complex that even the direction of tail movement is important.

In new studies show as well as dogs wag their tails to the right when they are happy or confident and to the left when frightened, and there’s a reason for that.


The left side of the brain controls the movement of the right side of the body and vice versa.

So, the left brain is engaged when the tail wags to the right and the right brain wags the tail to the left.

As the left side of the brain is associated with positive feelings like love and serenity, a happy dog wags its tail to the right.

Conversely, the right half of the brain is associated with negative feelings like fear and depression, like a scared dog wags its tail to the left.

Giorgio Vallortigara, a neuroscientist from the University of Trieste in Italy, and two veterinarians, Angelo Quaranta and Marcello Siniscalchi, from the University of Bari, published an article describing this phenomenon in the journal Current Biology.

The researchers recruited 30 mixed-breed dogs and placed them in a cage equipped with cameras that accurately tracked the angles of their tail flaps.

They then showed them four stimuli in the front of the cage:

  • Their owner
  • An unknown human
  • A cat
  • An unknown dominant dog

When dogs saw their owner, their tail wagged vigorously, with emphasis to the right side of their body, while an unknown human wiggled their tail moderately to the right.

Looking at the cat, the dogs’ tails wagged more to the right again, but more slowly and with more moderate movements.

However, the sight of an aggressive and unknown dog made their tails wag to the left side of their body.

It is important to understand that we are talking about the dog’s left or right when viewed from the rear as if you are facing the direction the dog is looking.

This finding is not as strange as you might think at first.

Research has shown that in many animals, including birds, frogs, monkeys, and humans, the left side of the brain specializes in positive emotions while the right deals with negative emotions (sadness, fear or disgust. ).

Why do dogs wag their tails?

Can tailless dogs communicate?

Dogs without a tail communicate but have limits.

Dogs without a tail are therefore more careful to approach other dogs or people to avoid misunderstandings.

They depend on other aspects of body language such as the position of the ears, facial expression, and their overall position to communicate their intentions.

Conclusion on dog tail wagging 

Although dogs do not speak the human language, they still communicate quite effectively, and wagging their tails improves their ability to communicate.

It is interesting to remember that dogs do not talk to themselves. They wag their tails in front of humans or other dogs, but they don’t wag their tails when alone!

Just like we don’t talk to ourselves… (maybe sometimes)!

Leave a Comment