Why Do Dogs Wag Their Tails?

Kieran Beckles
By Kieran Beckles
Updated on 14 January 2021
Expert Content

Have you ever pondered why your dog wags their tail?

They may do it when you get home from a day at work, or when you prepare their food at dinnertime.

Some dogs will wag their tails when playing with other canines at the dog park.

Most pet owners will commonly associate a dog wagging their tail as a happy or friendly pooch.

However, this isn’t always the case so it’s important that pet parents learn about the different messages that their dog’s tail is sending them.

We spoke to four experts, ranging from dog behaviorists to dog massage therapists, vets to dog trainers, to find out why dogs wag their tails.

Great Dane (Photo: Adobe Stock)

Great Dane (Photo: Adobe Stock)

Tails Are Often Misunderstood

Dale Buchanan, Certified Dog Trainer and Behaviourist

The tail is the most visible body part on many dogs, but is also the one that is most often misunderstood. For example, all tail-wagging does not automatically signify friendly intentions. As always, we have to look at the whole dog and the overall situation.

We need to first look at the tail height, and focus on the base of the tail – the thickest part, where it meets the rump – not the tip. Looking at the base of the tail in relation to the topline (the line made by the silhouette of the dog’s back) will give you a good indicator of tail height.

The tail by itself rarely tells you enough to know what the dog is feeling or saying.

As always, you need to look at all of the other key body parts and the dog’s movement overall.

Tail Height

• Lowered – Below the topline of the back Depending on how low the tail base is, this can signify: relaxation, lower confidence, submissiveness, cautiousness, uncertainty

• Tucked – As low as the tail can go, over the anus and in cases of extreme fear, sometimes even curled over the genitalia

• Raised – Above the topline of the back Signifies confidence, arousal (excitement), or alertness

• Raised High – Straight up over the topline of the back, or even higher, angled more towards the back. Signifies high confidence and/or high arousal

•Natural – The natural tail carriage for some breeds is extreme and this must be taken into account when using their tail as an indicator of emotions or intent

Tail Wagging

Not all tail-wagging is friendly. Look at tail motion within the overall context of the dog’s body and the situation.

Here are two examples of different extremes:

1) A relaxed tail (around level height) moving in wide or circular wags is a sign of friendliness

2) A stiff, high tail wagging very quickly in short motions may be a sign of tension and threat

Wants To Interact

Nicholas DeRoma, Consultant, Veterinary Technologist, and Canine Behavior Specialist at CatPet.Club

Many people associate tail wagging with a happy or friendly dog, however this is simply not always true. How the dog is wagging its tail often helps to determine why the dog is wagging its tail.

A dog wagging his tail indicates that he wants to interact – this does not necessarily mean it will be a positive interaction.

When a dog is wagging his tail with a high and stiff posture and small amplitude, this typically reflects a high state of arousal. This posture may indicate impending aggression. When the tail is low or tucked between the legs but stiff and wagging rapidly with small amplitude, the dog is communicating fear, anxiety, or appeasement.

These dogs may be unpredictable in some instances due to intrinsic conflict. Finally, loose and relaxed tail posture with a large amplitude, generally indicated friendliness and a willingness to play.

Parson Russell Terrier at the park (Photo: Adobe Stock)

Parson Russell Terrier at the park (Photo: Adobe Stock)

High And Stiff Tail

Jeff Carbridge, Dog Trainer and Expert at DogOwner

We all love a waggy tail, but what does it actually mean? It is a common question that I get.

When they are happy

This is our most common association with tail wagging – that violent back and forth when they are just filled with joy. They might be excited for a treat, playing, or happy to see you home from work. Their tail will usually be quite high up and wagging at a fast pace.

Fear and submission

When their tail is low down and wagging a little it means that they are frightened or being submissive. For example, if you just yelled at them for doing something bad you might notice this tail position alongside a lowered head and flatter ears.


Dogs who are curious will often have their tail straight out wagging slowly. This is also very similar to being alert, but alert and excited dogs hold their tail a little higher.


Dogs that are displaying aggression will often have a very high and stiff tail that does not wag. Instead, it is held in place and their ears will also be as far forward as possible.

It’s An Instinctive Behaviour

Dr Jamie Richardson, Medical Chief of Staff here at Small Door Veterinary

Dogs use their tails for a number of reasons – primarily to communicate, both with other animals and with us.

It’s an instinctive behaviour that develops between 3 and 4 weeks of age in puppies, initially to communicate with their mother and litter-mates.

You can think of it as a form of body language. In the way that humans can communicate with a smile, nod or frown, dogs use their tails. Researchers theorize that tail wagging may have developed as a communication method because dogs’ eyes are extremely sensitive to movement, and so they can pick up tail wagging as a visual cue very easily.

While a wagging tail can often signify happiness, it does not always. It can also signify nervousness, feeling threatened, anxiety, submission and excitement. It’s important to take into account how the tail is wagging (both speed and positioning) and your dog’s other body language.

Brussel Griffon were bred to hunt vermin in Belgian stables (Photo: Adobe Stock)

Brussel Griffon were bred to hunt vermin in Belgian stables (Photo: Adobe Stock)

You Need To Watch Other Signals

Colby Lehew, Certified Canine Message Therapist at Dogletics

You can not determine what a dog is feeling based on his tail alone. Instead, you must watch other signals dogs used to communicate between two dogs.

“Calming signals,” is a term coined by Norwegian dog trainer Turid Rugaas. These signals include body positions and facial expressions. For example, ears back, licking lips, scratching, turning away, and whale eyes can mean that the dog is stressed. There are positive signals such as blinking and play bow which means “I mean no harm”.

There are at least 30 calming signals and are universal with dogs. Humans can even use them with dogs. For example, rescue volunteers are taught to blink at a dog to provide reassurance to a dog. Overall, calming signals are used to seek reassurance, resolve conflict, and/or appease each other.

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