Wagging Is A Form Of Communication For Dogs
November 1, 2013

Dogs Can Differentiate Between Fellow Canines’ Tail Wags Based On Direction

[ Watch The Video: Silhouette Of Dog Wagging Tail ]

redOrbit Staff & Wire Reports - Your Universe Online

Though it might not seem like it to humans, dogs communicate different messages to their fellow canines when they wag their tails, according to new research appearing in Thursday’s edition of the journal Current Biology.

While previous research had revealed that dogs wag their tails more to the right (from the canine’s point of view) when they are happy and to the left when they are nervous, the authors of the new study report that other dogs can detect and respond to those differences, said BBC World Service Science Reporter Rebecca Morelle.

“To find out more about how dogs react to the lop-sided tail wags of other dogs, the researchers monitored the animals as they watched films of other dogs,” Morelle said. “When the animals saw an otherwise expressionless dog move its tail to the right (from the tail-wagging dog's point of view), they stayed perfectly relaxed.”

[ Watch the Video: Dogs Use Visual Naturalistic Stimuli ]

However, when the canines saw the dog in the video move its tail predominantly to the left, the animal’s heart rates became more rapid and they began to look anxious. Lead researcher Giorgio Vallortigara, director of the University of Trento animal cognition and neuroscience lab, told The Guardian that the reaction was most likely an automatic behavior and an intentional form of communication.

“The direction of tail wagging does in fact matter, and it matters in a way that matches hemispheric activation,” Vallortigara explained in a statement. “In other words, a dog looking to a dog wagging with a bias to the right side – and thus showing left-hemisphere activation as if it was experiencing some sort of positive/approach response – would also produce relaxed responses. In contrast, a dog looking to a dog wagging with a bias to the left – and thus showing right-hemisphere activation as if it was experiencing some sort of negative/withdrawal response – would also produce anxious and targeting responses as well as increased cardiac frequency.”

Despite his belief that the dogs are not overtly attempting to communicate their emotions to other canines, Vallortigara believes that dog owners and veterinarians could find practical uses for the discovery. “It could be that left/right directions of approach could be effectively used by vets during visits by the animals or that dummies could be used to exploit asymmetries of emotional responses,” he noted.

Dr. John Bradshaw, a visiting fellow with the University of Bristol's school of veterinary science, explained to Morelle that this is not the first study to examine the importance of left vs. right amongst canines. Last year, University of Lincoln experts reported that dogs turned their heads to the left in response to an aggressive dog, and to the right when looking at a happy dog, he said.

“While there is considerable evidence from many different mammals that the two sides of the brain are used for different purposes, much of the detail still has to be hammered out - and dogs are no exception,” Dr. Bradshaw told the BBC. “However, given the ease with which their behavior can be recorded, it will probably not be long before we understand why their tails sometimes go one way, sometimes the other.”