Tail wagging shows different emotions in dogs

New scientific studies have shown that the direction in which a dog wags its tail can show how it is feeling.
The study was carried out on 43 dogs of different breeds, who were fitted with heart rate monitors and filmed whilst they were shown two different videos. The first video showed a dog wagging its tail to the left, which caused an increase in heart rate and the presence of more stressed or anxious types of behaviours. In comparison, the second video showed a tail wagging to the right and dogs that were shown this video seemed more relaxed and had a lower heart rate. 

It has also been seen that dogs wagged their tails to the left more often when faced with something they did not want to approach, such as another dog showing aggressive behaviour, and to the right when faced with something they liked, such as their owner. 

Scientists believe that this link is due to the different roles, and increased activity, that the left and right hemispheres of the brain have in different situations. This can also been seen in humans and are responsible for the emotions we feel under certain circumstances. Scientists are unsure if these directional tail wags are intended as a signal to other dogs, or whether they are simply a by-product of the use of different hemispheres of the brain. It is hoped that some practical uses could come of these findings for example; a veterinarian may be able to approach a dog from a preferred side to avoid aggression, or for teaching or training purposes. 

The results were published on October 31st 2013 in the journal Current Biology.