Why Do Dogs Wag Their Tails?

Animal tails serve a number of functions from maintaining balance to (in the case of fish) to swimming through water. Tails can also be used to communicate emotion and intent, for example through tail-wagging.

This behaviour is common in many animals: Cows, pigs, and horses might wag their tails to shoo away flies, birds do so to ward off predators - while in cats, tail-wagging can indicate annoyance.

Tail Wagging In Dogs

Dogs are often associated with this behaviour - but why do dogs wag their tails? While this behaviour is instinctive, puppies tend not to wag their tails until they are around three-to-four weeks of age.

Along with their wild cousins (wolves and foxes), tail-wagging in domesticated dogs is somewhat similar to the human smile, conveying a range of messages from polite greeting to cheery welcome.

Happy Tails - How To Read Your Dog

Whether their pack includes humans or companions of the same species, this form of canine communication can be used to express a range of positive emotions.

● Broad, mid-air, sweeping: This suggests a dog is happy and relaxed.
● Rapid, side-to-side (often while sniffing something out): Focused; in “hunting mode”
● Low, gentle: Curious (but cautious).
● Helicopter tail: Not ready for take-off - but very pleased to see you!
● High, quick wagging: excitement

Dogs can also wag their tails with such enthusiasm that their entire back end starts to wiggle! Some dogs are lifelong wigglers, while others become more reserved as they age, saving their energy for their closest friends.

Signs Of Stress

Another question might be: why do dogs wag their tails if they seem unhappy? If tail wagging is accompanied by the following behaviours, it may be that your dog is under stress:

● Aggressive expressions such as snapping, bared teeth or growling.
● Tail height (this can be an attempt to look bigger when faced with a potential threat).
● Lip-licking, yawning (when not tired).
● Raising a paw (more tentative than the paw-lift seen when hunting or stalking).
● Appeasement behaviours such as averting their gaze, cowering, hiding or moving away.

If your dog’s tail is tucked or between their legs, this tends to be a self-protective gesture when feeling threatened - although in addition to the context of the situation and other body-language cues, tail-related behaviours can also depend on the breed of dog.

Many Different Tails

The natural position of sighthound breeds such as whippets and greyhounds is to keep their tails low (they may even tuck them under when content). Similarly, terriers and beagles tend to hold their tail high when happy - although in many breeds this signifies aggression.

Tail positions also depend on the situation: some breeds such as shih-tzus (and other, larger breeds like huskies) have feathery tails that curl towards the body, giving a pom-pom-like appearance often indicating happiness. An unfurled tail can show stress - though it can also be tiredness or relaxation.


Historically, amputation or removal of the tail, or “docking” - was thought to have benefits that have since been disproved - such as increased speed or protection from rabies. Later, tail-docking was carried out for cosmetic reasons and prevention of injury to working breeds.

While tail-docking of certain working breeds continues to this day (within strict legal and medical guidelines), it is a highly controversial practice - not only because research suggests that its use is ineffective - but it also causes dogs unnecessary suffering and affects their ability to communicate.

Left And Right Tail-Wagging

A study conducted in 2013 suggests the direction of a dog’s tail can also tell you about their mood. The study, which was carried out on 43 dogs of varying breed, who were shown videos of dogs wagging their tails to the left or right.

The study showed that while left tail-wagging indicated stress, right tail-wagging was overall more positive. This is because the left side of the brain controls the right side of the body (the hemisphere that affects positive-approach emotions), and vice-versa.

Body Language - Top To Tail

In conclusion, why do dogs wag their tails? Primarily, to communicate, although it’s important to note that the meaning of tail-wagging depends on what the rest of their body is doing, as well as the context of the situation and the particular breed.

While dogs can understand a surprising amount of human words, they can’t talk back. That said, a dog’s body language can tell you a lot about how they are feeling and what they might want to tell you.

In addition to learning your dog’s body language, taking them for a walk offers a great chance to bond while socialising with other pets. In addition to other walking accessories like dog leads, our dog crate collection can help to settle a new pet into your home.

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