Telling Tails: What does dog tail wagging mean?

Posted by Dr Dog. April 24th 2017.

All dog owners love that wagging tail welcome from their four-legged friends. But, contrary to popular belief, dog tail wagging doesn’t always mean happiness.

dog tail wagging

Scientists have discovered that dogs use tail wagging as a communication tool. There are different wags for different messages, and we need to tune in to understand what the messages are.


Don’t get us wrong; some tail wags are associated with happiness or greeting. However, others can communicate fear, insecurity or a warning not to come closer. The position of the tail, speed and pattern of movement can all help us understand the social signals of dog tail wagging.


Here’s a basic guide to dog tail wagging and its many meanings – how many do you recognise?


Common happy wags


Type of wag: Tail held horizontally, small slow wag from side to side

Meaning: Positive but tentative greeting.


Type of wag: Tail held low or horizontally, broad fast wag from side to side (sometimes makes the whole body appear to wag!)

Meaning: Friendly, welcoming and pleased to see you. The most common ‘happy wag’.


Common unhappy wags


Type of wag: Tail held slightly higher than horizontal, fast wag

Meaning: Insecure, unsure about your or another dog’s presence


Type of wag: Tail held high, tiny high-speed movements from side to side

Meaning: Threat or warning not to come closer


Other dog tail wagging types


Left wag, right wag

There’s another discovery that has surprised many dog owners and scientists alike. The direction bias in which a dog wags its tail can also indicate its emotions. A group of neuroscientists at the University of Trento conducted research that showed dogs’ tails tend to move slightly more to the right if they’re happy. Likewise, if the dog feels negative emotions like fear or aggression, the tail tends to move further to the left.


This can be tough for even the most attentive dog owner to detect and interpret, and is more readable for other dogs than it is for humans. However, if you do notice your dog’s tail wagging is more biased to the left or right, this is a good indication of how they’re feeling.


Tail up, tail down

Dogs’ tails don’t even need to be wagging to tell us how they’re feeling. If a dog’s tail is horizontal or low, the dog is in a neutral to submissive mode and will usually be good-natured.


If, however, you see a dog with its tail high in the air, this is a signal of dominance and assertiveness – as if to say ‘I’m in charge here!’ Approach these dogs with caution, especially if you have another dog with you, as this is challenging behaviour and could lead to a fight.


So it turns out dogs’ tails are more than just the wiggly appendages that knock our drinks off coffee tables. If we’re able to recognise the social signals our dogs are giving us using tail wagging, we can have a much more rewarding and understanding relationship together.


To find out more about dog behaviours, check out our dog blogs by Betty, our resident canine behaviour expert. You can also find out everything you need to know about dog insurance policies on our main website at

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