At the Vets: How your dog’s tail can reveal how he’s feeling ...

Big happy tail-wagger Jez!
Big happy tail-wagger Jez!

Unsurprisingly I meet a lot of dogs in my line of work. And most of the time their noses are wet, tails will wag, and much sniffing occurs – especially if a treat’s involved.

But now scientists think they’ve spotted some subtle differences in tail wagging, for example, what a wag more to the right actually means; what’s more they’ve even got evidence to prove it.

A recent study has not only identified particular wagging patterns that indicate how your dog’s feeling - in a positive or negative way - but that other dogs observe those patterns and will react to them too.

To bring you up to speed, current ‘wagging rules’ state that if the tail wags slightly to the right the dog is indicating feelings of calmness and enjoyment, whereas a left bias in the tail wag tends to signal anxiety and feeling upset.

So, armed with this knowledge, scientists then tested to see if dogs pick up on each other’s tail wagging - and by how much.

A group of 43 dogs wearing heart rate monitors were shown movies of other dogs exhibiting different tail wagging behaviours as well as silhouettes of dogs that the scientific team could specifically manipulate; what they discovered was quite intriguing.

When their dogs saw otherwise expressionless dogs wagging their tails to the right, they remained perfectly relaxed; but when the test dogs saw other dog’s tails veering to the left, heart rates rose and they became visibly anxious – thought to be unintentional subconscious communication.

As to why left and right tail wagging should signal such strong differences in emotional messaging, it appears to be a matter of what area of the brain’s engaged – just like left and right sides of human brains - differently involved in stimuli invoking positive or negative emotions.

It seems dogs pick up on this when they meet other dogs forming a type of communication between them.

It’s hoped that this research will help dog owners, animal behaviourists, even us vets to better understand and respond to the wide range of moods and expressions exhibited in canine behaviour.