We often think of a ‘waggy tail’ as being a sign of our dogs being happy, but recent research has shown that tail wagging doesn’t purely convey a dog’s happiness. The tail of a dog is a communicative tool that they use to express emotions to other animals, and indeed, us as owners. Vets have been suspicious that wagging isn’t always related to happiness for some time – often at the vet dogs that are notably nervous or defensive will have a wagging tail. This can often be misinterpreted – leading to a very dangerous situation for both veterinary staff and owners alike.
why do dogs wag their tails?
Dogs will wag their tails to convey a variety of emotions: happiness, nervousness, feeling threatened, anxiety, submission, and excitement.
It is believed that when a dog is relaxed, its tail sits in a resting position. this position will vary depending on the breed of dog. some dogs have a naturally curly and stiff tail, and others may have a long tail that falls behind them in the natural position. when emotions are evoked, tail wagging occurs.
Studies have shown that the rhythm and position of movement often convey emotion.
If a dog is frightened or submissive, they will often lower their tail and possibly wag it between their legs a bit. We are familiar with this image of a dog who has been scolded by his owner, looking very sorry and guilty!
Dogs that are alert or excited will hold their tails higher than the natural position. Often this tall tail will wag furiously; a quick movement will often mean a dog is happy or excited. again, this is something we often see at the park or when playing with our dogs. they often strike a playful stance with their butts up, wagging a high tail as they ask us to throw a ball or play tag. this behavior is also seen when we greet our dogs after being away for a long time: they tell us that they missed us and that they are glad to have us home!
A curious dog that is interested in its surroundings will often hold its tail up.
an aggressive dog usually has a very stiff vertical tail.
Recent research shows that the direction of tail wag can communicate complex emotions to other dogs. By monitoring the behavior of “watcher dogs” who were watching another individual wag their tails, dogs have been shown to convey positive emotions to each other by wagging their tails slightly to the right. on the other hand, more negative emotions are experienced if a dog moves slightly to the left.
Observing dogs were shown to have a slower heart rate and a more relaxed posture when shown images or silhouettes of dogs wagging their tails slightly to the right. if they were shown a dog wagging its tail slightly to the left, the observing dogs would have a rapid heart rate and adopt a more defensive posture. some of the observing dogs were even seen to have goosebumps at the sight of a dog moving further to the left!
Research in other species, including humans, has shown that the left side of the brain controls positive emotions and the right side controls negative emotions. strangely in all animals, the right side of the brain controls the left side of the body, and vice versa. therefore, the theory about left and right movements conveying emotion is thought to have to do with the brain’s “hard wiring” with different sides controlling different emotional responses.
Queues aren’t just for communication…
It’s worth remembering that dogs don’t just use their tails to communicate. It is often used to aid in balance and stability: Watching a dog spin at high speed in slow motion can often reveal how he uses his tail to maintain stability. it also acts as a rudder if the dog is swimming in the water. it is interesting to consider whether the use of a tail as a means of communication has evolved secondary to these uses, or whether dogs’ tails first evolved as a means of communication.
Finally, the most important thing to remember is that tail wagging does not necessarily mean a happy or friendly dog. Tail wagging is simply a sign that a dog is interacting with its environment. It’s always vital to talk to a dog’s owner before petting them, as misreading the tail wag can often lead to a nasty bite. Children are often the victims of such misunderstandings, so it is vital that we all ensure that they are aware that they should only touch a dog if they have been told it is allowed.