Why do dogs wag their tail, and what is your dog's tail saying?

Dogs wag their tails when they’re happy—that’s pretty much the sum of it, right? Actually, no.

Our tailmates use wagging as a complex form of communication—to express joy, for sure, but also to convey a wide range of other emotions. If you’re looking to understand your tailmate's body language, knowing what their wag is saying is a great way to start. 

Here, we answer "what does a dog wagging their tail mean?" and help you decode your tailmate's wags.

Key scientific takeaways on canine tail wagging

Wagging is communication, not reflex

Tail wagging is a complex, intentional way for our dogs to communicate with us; it’s not just a reflection of excitement or happiness. Interestingly, when a dog is completely alone with no one to interact with it won’t typically wag its tail, whether happy or not. Think of the tail as a communication tool, rather than a reflex action.

Direction matters

Where the tail wags, like left or right, matters. It’s linked to a dog’s brain activity, like positive or negative emotions.

The type of wag matters, too

Speed and height are also important parts of your tailmate's body language, and you can gain insight from it.

Debunking the myth: does a wagging tail always mean happiness?

No, a wagging tail doesn’t always mean a dog is happy. A high-held wag can mean aggression or alertness, for example, while a slow, low wag can mean anxiety or insecurity.

The basics of your dog's tail wagging

Dogs have a rich emotional life, and researchers have found that tail wagging is a common and multifaceted way for them to express those emotions.

A wagging tail can express anything from joy and excitement to anxiety, aggression, and apprehension. And believe it or not, the WAY a dog wags—including tail speed, direction, and height—can show you what they’re feeling at any given moment.

For instance, a tail wagging vigorously at mid-height might indicate a friendly and excited disposition, while a slow wag with the tail down could suggest insecurity or a submissive attitude.

The movement of a dog's tail can vary greatly, with each variation offering clues about their mood. By paying attention to these details, dog parents can gain a better understanding of their pup’s needs and emotional state.

Dog tail meanings, decoded

To understand the meanings of different types of wags, we can actually turn to some scientific data. Let's delve into the specifics. 

• Rapid, mid-height wag: This wag is pure bliss. It signals joy or excitement and it’s often seen when dogs greet their owners after they’ve been gone for a while. 

• Slow, lower wag: This more subdued tail action can indicate uncertainty or even mild anxiety, especially in situations that are new or less familiar to them. It’s a subtle kind of wag, but recognising its meaning will help you comfort or reassure your tailmate when they need it. 

• Stiff, high-held wag: Beware: a stiff, high wag is a sign of potential aggression or alertness to perceived threats. It’s a dog’s way of setting boundaries, serving as a visual cue for humans and other animals to maintain distance. Whatever you do, don’t mistake it for a sign of happiness or approachability. 

• Attention-seeking wag: When dogs want playtime, affection, or even just some attention, they may wag their tails in a manner that invites interaction. Look for an animated and exaggerated side-to-side tail movement, often at lower to mid-height and at a moderate to fast pace. This may also be accompanied by other signs of eagerness, such as a perky posture, a wiggling body, or playful barking. 

Wags don’t tell the whole story, though. You'll need to consider your tailmate's wagging along with other cues like ear alignment, gaze direction, and stance, you can gain an even deeper understanding of your dog’s feelings and intentions and respond to their emotional needs more quickly.

The science behind tail-wagging in dogs

Believe it or not, neuroscientific researchers have concluded that the direction of your dog’s wag means something. For example, research by Giorgio Vallortigara found insights in lateralisation - moving left or right - suggesting that the side of the wag indicates happiness or unhappiness.

For example, a right-sided wag has been noted in dogs that are joyfully greeting their pet parents, while a left-sided wag has been seen with negative emotions, such as confrontation with an aggressive, unfamiliar dog.

Just as the direction of a human’s lip curl signals happiness (smiling) or sadness (frowning), the various characteristics of canine tail wags are deeply embedded in their neurochemistry, with specific movements reflecting consistent emotions and intentions across breeds and individuals.

Studies also suggest that tail wagging serves various purposes in social interactions among dogs. The direction, speed, and height of a wag can convey specific messages to other dogs, influencing social dynamics within a group.

It’s also worth noting that humans smile and talk to be socially polite and some dogs may wag their tails for similar reasons. Looking at the rest of their body language and positioning can give more detailed clues about how they are really feeling.

Understanding these subtleties can help you gain a deeper appreciation of your dog's behaviour, and it also shows that our tailmates have rich, complex emotional and social lives (as if we didn't know that). 

Beyond tail wagging: dog body language

Tail movements are just one piece of the puzzle. Considering your dog's tail signals in conjunction with other body language cues can enhance your understanding even more.

Always consider context alongside your dog's tail wag. For instance, a tense encounter with another dog will yield a different kind of wagging than a joyful play session with your dog’s favourite toy. 

It's also important to consider variations in tail wagging that may reflect your tailmate's personality and breed-specific traits. Some breeds, like Beagles, and Pugs, naturally carry their tails higher or wag more vigorously, which can influence how their tail signals should be interpreted.

In addition to maintaining situational awareness, you should consider other physical cues, like ear position, eye contact, body posture, and vocalisations. This holistic approach lets you respond more effectively to your dog’s needs, which helps you establish a happier and more secure environment for both of you.

You know your tailmate best, and you're both in sync with each other, so we're sure you'll know how they're feeling.

What tail wagging says about your dog's health

Amazingly enough, your dog's tail wagging can help provide insights into their physical health. Changes in tail movement, like a decrease in wagging or a tail held in an unusual position, can indicate discomfort or pain. A tail that's tucked under might suggest fear, but it could also signal a canine health issue. 

Abnormal tail movements can reflect serious conditions like infections, injuries, or neurological problems. For instance, a limp tail, often called "limber tail syndrome," can result from overexertion, cold weather, or swimming, indicating muscle strain or injury.

An unusually stiff tail, or one that doesn't wag in scenarios where you'd expect it to, might suggest spinal issues or internal problems.

Regularly monitoring how your dog wags their tail (along with other behaviours) can help you determine when it’s time for a vet visit. If you're ever worried, see your vet.

Fostering a waggier bond with your tailmate

Understanding your dog's tail wagging offers a glimpse into the emotional world of our tailmates and their physical well-being, fostering a deeper connection between you and your pet.

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