Why Do Dogs Wag Their Tails?

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In addition to the placement or position of the tail, you should also pay attention to the movement of the tail. A good general rule is that greater intensity/speed of wagging indicates higher levels of excitement, which (again) is not necessarily a positive emotion.

Imagine knocking on a new friends’ door for a dinner party and being greeted not only by your host, but also by their bounding Golden Retriever! If you’re a dog person, this might mean that you’re in for a great night of hanging with a new canine companion, and the fact that their tail is wagging at the sight of you may give you the confidence to bend down and give his head a scratch.

However, despite what so many people feel when they see a dog swinging its tail back and forth, it isn’t a universal sign of friendliness, nor an open invitation to approach or touch that particular pooch. Tail wagging is a language unto itself, and one that you should thoroughly understand before you give a strange pup a scratch behind the ears.

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Why Do Dogs Wag Their Tails?

Although it would be awesome if our pets could speak to us in our native tongues, it’s not a realistic expectation, but they still need to communicate with us in some way. There are plenty of ways that dogs express their needs, such as scratching the door when they need to go out, jumping on the bed when they’re hungry in the morning, or licking our face when they haven’t seen us in days (or minutes). However, there are few more versatile or expressive methods of communication as a dog wagging its tail. If you’ve never had a dog, you may not know how varied the wagging of a tail can be, but veteran dog owners know that their pets can say a LOT by moving their tail in particular ways.


Before we get into the details of different tail-wagging styles or intensities, we should talk about the fundamental act of moving the tail. At the very basic level, a dog wagging its tail is demonstrating a sign that they are engaged. The dog is paying attention to a situation and is willing to interact, whether you are an animal or a human being. When dogs are left alone at home, their tails won’t be wagging, as there isn’t any stimulus with which to engage. Now, it is important to remember that an interest in engaging with a situation or an environment isn’t necessarily a sign that a dog is friendly or eager to be touched.

Furthermore, you shouldn’t assume that all dogs’ tails are communicating the same things. Even if you’ve had a dog for many years, other dogs will differ in terms of breed, range of tail movement, level of training, and personal history of trauma or treatment. A tail wag “style” you think you recognize from your pup may mean something completely different from another dog. You can think of tail wagging as a language with many different dialects; you might not be able to understand all of them, as the meaning of certain “words” or “phrases” will vary.

Also Read: Why Do Dogs Lick People?

Deciphering The Language

Elevation and motion are the two key aspects to consider when looking at a dog’s tail, particularly if you are trying to decipher what mood they are in, or what they’re trying to communicate.


If a dog’s tail is in a normal or neutral position, it will usually be relaxed and hanging loose near their heels. Some breeds may differ, based on their tail structure, but this is generally the natural position when a dog isn’t being stimulated or attempting to express itself. If a tail is held above the natural level, it could indicate some level of excitement or engagement, while a tail held straight up is often a sign of wariness or potential aggression, such as when your dog smells another animal in the woods. As someone approaching a new dog, if their tail is pointed straight up, it should be taken as a sign of dominance, or even a threat. In other words, proceed with caution.

If the dog’s tail is being held under its body, it demonstrates a submissive or nervous attitude, and could also indicate if your pup isn’t feeling well, or is experiencing a fear response. When a dog holds its tail out straight, it often signals curiosity, or the desire to explore something more fully before making a judgment. Again, these are general guidelines for what these tail positions mean, but it’s always best to become familiar with a dog’s personality, or speak with their owner directly, before making any assumptions about their mood or behavioral patterns.

Dog fearful behavior icon. Domestic animal or pet tail language(Double Brain)s
An illustration of dog manifesting fear by helding its tail under the body (Photo Credit : Double Brain/Shutterstock)


In addition to the placement or position of the tail, you should also pay attention to the movement of the tail. A good general rule is that greater intensity/speed of wagging indicates higher levels of excitement, which (again) is not necessarily a positive emotion. A slower wag can indicate suspicion, particularly when the tail is held loosely, or straight away from the body. In this case, you may want to be careful with how quickly you approach, as the animal may be tentative about your presence.

You must also look at the breadth of the tail wagging, how forceful or firm the tail is while moving, and other body language indicators from the dog, such as bared teeth or growling.

If the tail is wagging back and forth gently, with a relatively small sweep, the dog is starting to communicate, akin to asking you to play or engage, or merely saying hello. When the breadth of the tail sweep increases—the luxurious “wagging” that most of us associate with a happy dog—it is likely an indication that the dog is pleased or comfortable, and is welcoming you in for a scratch or a pet.

Aside from elevation and motion, a third element that has been recently identified is the tail’s position on the right or left side of the dog’s body. If a dog’s tail is primarily wagging on the right side of their body, it indicates a positive feeling, while wags on the left side suggest a negative response. While this is a somewhat new development, the research is strong in support of this emotional preference. This aspect is believed to be related to the different sides of a dog’s brain operating more strongly depending on mood, which manifests as a physical preference in tail wagging!

Also Read: Why Do Dogs Tilt Their Heads?

A Final Word

There will likely never be a foolproof way of communicating with animals, but understanding the well-studied meanings behind certain behaviors, such as tail wagging in various forms, will help you read situations and animal emotions more effectively. It might be tempting to kneel down and let every dog come bounding into your arms, but caution and respect are required!

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References (click to expand)
  1. What a Dog’s Tail Can Reveal About Its Brain | Helix Magazine - helix.northwestern.edu
  2. Tail Wagging– what does it mean? | SiOWfa15. The Pennsylvania State University
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About the Author

John Staughton is a traveling writer, editor, publisher and photographer who earned his English and Integrative Biology degrees from the University of Illinois. He is the co-founder of a literary journal, Sheriff Nottingham, and the Content Director for Stain’d Arts, an arts nonprofit based in Denver. On a perpetual journey towards the idea of home, he uses words to educate, inspire, uplift and evolve.