What Does Your Dog’s Tail Wagging Really Mean?

Does your dog’s tail swish more to the right? Or, lately, is your solemn pooch a left leaner? Scientists think they know what these subtle differences mean, and what’s more they’ve got evidence to show other dogs do too.

Any dog lover can tell you that far from being simple creatures, dogs appear to exhibit a wide range of moods and expression, from charging around one minute to being a cautious canine the next.

Now, in a study published in the journal Current Biology, scientists have not only identified particular tail wagging patterns that can indicate your dog is feeling in a positive or negative way, but that other dogs not only see those patterns but react to them too.

This is built on previous research that indicates a dog whose tail wags slightly to the right tends to be exhibiting calmness and even enjoyment, whereas a left bias in the tail wags tend to signal anxiety and upset. Armed with this knowledge, scientists devised an experiment to see if dogs pick up on each other’s tail wagging, and by how much.

To do this, the team of Italian scientists showed a group of 43 dogs wearing heart rate monitors movies of other dogs exhibiting different tail wagging behaviors as well as silhouettes of dogs that the team of scientists could specifically manipulate. What they found was quite intriguing.

Photo credit: It'sGreg.

Dogs Read Tail Wagging Automatically

When the 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, their heart rates rose and they became visibly anxious.

The scientists don’t believe that this is a form of intentional communication but rather more a version of the body language we are familiar with among humans and what we often unconsciously process.

Professor Georgio Vallortigara, a neuroscientist from the University of Trento who was head researcher in this investigation, is quoted as saying he believes this reading of other dogs’ tail wagging behaviors is likely a learned ability:

“If you have several meetings with other dogs, and frequently their tail wagging one way is associated with a more friendly behavior, and the right side is producing a less friendly behavior, you respond on the basis of that experience.”

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 is being engaged.

“It is very well known in humans that the left and right side of the brain are differently involved in stimuli that invokes positive or negative emotions,” Vallortigara is quoted as saying. “In dogs, single organs like the tongue or tail is controlled by both sides of the brain. There can be competition and dominance between these two sides. When they move their tail, it is more bias to the left or to the right depending on which side of the brain is more dominant at the time. It seems dogs pick up on this when they meet other dogs and it forms a type of communication between them.”

Decoding the Tail Wag: How This Insight Could Help Dog Owners

It is hoped that this research could help dog owners, animal behaviorists and vets to better understand canine behavior. In particular, the scientists believe it could be used to read and respond to a dog’s stress levels when visiting the vet. Furthermore, the scientists suggest that dummies could be made to simulate calming tail wags to sooth a stressed dog — so don’t be alarmed if, in a few years, you walk into a vet’s office to find a plastic pooch wagging its tail to the right.

The researchers point out, however, that thier tests were limited. As such, their future investigations will be geared toward assessing tail wagging among live dogs to see if this yields a more varied set of wagging behaviors.

Who knew that a dog’s wagging tail could be so interesting?

Photo credit: Thinkstock.


natasha p
Past Member 18 days ago

cute pic!

Jim Ven
Jim V2 years ago

thanks for the article.

Carrie-Anne Brown

thanks for sharing :)

Lynn C.
Lynn C4 years ago


Lisbeth Alvarado Sanchez

Dogs are wonderful intelligent creatures.

Spencer Young
Spencer Young4 years ago

A tail of two Pitties. You wont be able to put it down

Spencer Young
Spencer Young4 years ago

Thanks for the tale of the tail, it was dog gone good

Cathleen K.
Cathleen K4 years ago

Interesting, not least because it establishes that dogs can gather meaningful information from two dimensional dogs on screens!

Natasha Salgado
Past Member 4 years ago

Very interesting but logical. Will be sharing this with my doggie pal friends! Thanks

Suzan F.
Suzan F4 years ago

I've had dogs all my life. I don't need a paid study to tell me what certain wags mean. Hell...pay me, & I'll tell them what wags mean. There's a thought.