Why do dogs wag their tails?

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 If there’s one thing we all know about dogs, it’s that they wag their tails. Regardless of whether you’ve got a tiny Chihuahua or a giant Great Dane, that tail will be wagging a mile a minute at the sight of their favourite snack or toy. But although we know all dogs wag their tails, have you ever wondered “why do dogs’ tails wag?”

If you have, you’ve probably assumed it just means that your dog is happy and healthy. However, it turns out a waggy tail doesn’t always mean a jolly pup. So why do dogs’ tails wag, and what does it actually mean?

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Why do dogs' tails wag?

Dogs’ tails wag because it’s a major form of communication with other dogs and people.

Dogs are highly visual animals, despite the fact their eyesight isn’t great. They learn as much about other dogs from watching their body language as they do from sniffing their butts. And although a dog’s eyesight isn’t very sharp or colourful, it’s highly sensitive to movement. That’s why tail wagging is such an important part of doggy body language, it’s easy to see and acts like an emotional barometer.

So, we know why dogs’ tails wag, but what does it mean?

Although we humans normally think a waggy tail is a sign of a happy dog, your pooch can actually communicate loads of different emotions with a waggy tail including happiness, excitement, curiosity, anxiety, and aggression.

Do dogs learn to wag their tails?

Tail wagging is instinctive in dogs, but they aren’t actually born with waggy tails.

Just like how human babies have to watch and learn different expressions from adults and take months to learn to talk, your puppy has to learn canine expressions and communication from other dogs as they grow up.

Different breeds learn at different speeds, but most dogs get the hang of wagging their tail by the time they’re 3 to 4 weeks old.

Do dog’s tails wag automatically?

Your dog has dozens of different muscles which control their tail, and they can control these muscles to move their tail. In fact, your dog can control the direction, placement, and even the speed of their wagging.

But even though we know dogs can control their tails, we aren’t completely certain whether all waggy tails are conscious or not!

That’s because even though dogs have control over the movement of their tails, they don’t always seem to think about needing to wag it. There is every possibility that wagging can be done subconsciously or involuntarily, similarly to how we humans will often smile or laugh without really thinking about it.

At the end of the day, tail wagging seems very similar to our own facial expressions, and it could be a mix of both conscious and subconscious expression.

What does it mean when a dogs’ tail wags?

Although we humans think a waggy tail means a happy dog, it isn’t always true!

Tail wagging can mean many different things based on the position of the tail, the speed of the movement, and even the direction that the tail is moving. By looking at your doggy’s tail, you can tell if they’re happy, sad, nervous, excited, aggressive, tense, or even curious.

Here’s a quick guide on what the wag means, and how you can read your dog’s emotions from what their tail’s doing.

How to read your dog’s tail

A stiff vs relaxed tail

A stiff wagging tail often means a dog is tense. They may be nervous, uncomfortable, or aggressive. Meanwhile, a relaxed tail that moves freely and easily from side to side is usually a positive sign and indicates a happy and relaxed dog. So remember, a relaxed tail means relaxed dog, but a tense tail means a tense dog!

How high are they wagging their tail

The height that your dog wags their tail at can mean different things too. If your dog’s tail is held high, it usually means they’re confident, excited, or mentally aroused. However, an erect and very upright tail is a sign of aggression. So the higher your dog’s tail, the more unpredictable their behaviour may be.

On the other hand, a low tail is a sign that your dog is sad or nervous. We almost all know that a dog with its tail between its legs is scared, hence the saying that someone ran away “with their tail between their legs”.

Meanwhile, some dogs might hold their tail straight out behind them, somewhere in the middle. This usually means they’re curious about something.

How fast are they wagging

Although your dog’s tail position is important, the speed of their wagging can mean a lot too. Often, a dog with a fast-wagging tail is excited. On the other hand, a slowly wagging tail can mean that your dog is uncertain.

Short and sharp tail movement indicate nervousness or tension, and it’s often associated with a dog in the flight or fight response. That means if your dog’s tail has short but very fast wags, they’re in a state of high alert and could be overexcited or aggressive. If the tail is held straight up like a flagpole and it’s wagging fast, it could be a sign of aggression.

Where does the wag go

Research has shown that the direction your dog wags their tail also indicates how they’re feeling.

If your dog’s tail wags to the left, it’s associated with negative emotions like anxiety or aggression. A tail that wags to the right indicates positive emotions and friendliness.

But not only will your dog wagging their tail to one side show how they’re feeling, it impacts other dogs around them too. If your dog sees another dog wagging their tail to the left, they’re more likely to become anxious themselves. But if they see a dog with a tail wagging to the right, they will usually be more relaxed and might even go over to say hello to the other pooch.

However, if your dog’s tail is going from side to side, the position and tension of the tail will tell you how they’re feeling.

The “neutral” position

Finally, a dog will have a neutral tail position. It’s a bit like an “off” position, and it’s where their tail naturally sits or hangs when they aren’t consciously moving it, a bit like how our arms usually hang by our sides.

A neutral tail usually means your dog is pretty chilled out, but the position of your dog’s relaxed tail will depend on their breed.

For instance, a Pug’s tail will naturally be high and curly, while a Shih Tzu’s tail curves over their back. A Whippet’s tail hangs low and slightly between their legs, but a Labrador’s tail is held out behind them.

Because different breeds have different tail positions, there is speculation that dogs might get a bit confused when they’re trying to interpret another breed’s tail talk. (Maybe it’s like a different accent!) However, dogs have other forms of body language they use too, so it’s important to consider their overall body language to determine their mood.

You’ll soon realise what’s “normal” for your pup’s tail, and it’ll be where it hangs out most of the time when they’re at home.

Why do dogs’ tails wag when they're happy?

Although a waggy tail doesn’t always mean your dog is happy, a lot of the time it will be. A happy tail will be relaxed and swooshing from side to side, without any sign of tension and no sudden or sharp movements. But why do dogs’ tails wag when they’re happy?

Dogs wag their tails when they’re happy for the same reason that we humans smile, it shows other dogs and people that they’re feeling good.

Dogs are social animals, and wagging their tail is one of the ways they communicate to others. As discussed above, it isn’t always conscious either, so your pooch might have a tell-tale tail!