The Tale Behind Dog's Tails

Have you ever wondered why your dog has a tail? Maybe your dog does not have a tail, and you've wondered why he is bereft while so many of his canine brethren are blessed with that extra appendage. What purposes do dogs' tails serve? Why do some dogs have them and some don't? Are dogs without tails at a disadvantage?

August 10, 2021 • BaxterBoo Team

It turns out that tails serve several different purposes, that tail-wagging is a learned activity, and that some dogs are born without tails, while others have them removed at a young age.

What Is the Purpose of a Dog's Tail?

Most people are aware of a dog's tail primarily as a means of communication. It is one of the most obvious ways that dogs communicate their emotions to humans and perhaps the least likely to be misinterpreted. A broad waving of the tail indicates that the dog is happy and excited, such as at the prospect of a new toy or treat . A tail tucked between the legs means that the dog is feeling scared and submissive. If the tail is straight up, with a vibrating movement rather than a broad wag, it means the dog is tense and in a state of arousal, a potential danger sign. If the tail is lower and wags only slightly, it means the dog is unsure about the situation.

A dog's tail is a communication marker not only for humans but for her canine fellows as well. A study in which pets at a dog park were greeted by a robot dog with either a long or a short tail showed that processing visual cues from the long-tailed robot was much easier and faster for dogs compared to interactions with a short-tailed specimen.

Dogs use their tails for communication in another way that humans may not be aware of. Canines experience and interpret the world largely through their sense of smell. Each has a unique scent produced by special glands on his hindquarters. When the tail wags, it helps to waft this scent around the dog's surroundings. This is one reason why submissive dogs tuck their tails between their legs; the gesture helps to prevent their scent from getting around. Dominant dogs, on the other hand, keep their tails upright, the better to diffuse their scent.

However, communication is not the only reason why dogs have tails. The appendage serves as a counterweight that helps dogs to keep their balance when walking along a narrow surface or taking a sharp turn at high speeds.

When Do Dogs Learn To Wag Their Tales?

While dogs have the ability to wag their tales when they are puppies, they do not do it when they are very young. It appears to be a behavior that they learn while socializing with their littermates around the age of four to six weeks old. This is when puppies start learning dog language and that their actions toward others may have unintended consequences.

Feeding is a situation in which conflict among puppies may be likely to arise. The mother's teats are very close together, which requires the older puppies to crowd close. At this age, puppies learn to wag their tails as sort of a flag of truce, to indicate that they want the situation to remain friendly and peaceful, and to appease any aggressive feelings that may arise among littermates as they all jostle together for position.

The extent to which tail-wagging behavior is learned from the mother versus being an instinctual behavior is not clear. Both nature and nurture may be at play.

Why Do Some Dogs Not Have Tails?

There are some breeds that do not have tails because they were born that way. Dogs such as the Boston Terrier, King Charles Spaniel, Pembroke Welsh Corgi, and Australian Shepherd all have a genetic mutation that causes them to be born with either very short tails or none at all. Because the breed standard calls for short or nonexistent tails, these dogs are selectively bred to maintain this genetic mutation.

However, there are other breeds of dogs that have long tails at birth that are often removed while they are still puppies. This is a procedure called docking, and while it is still common in the United States, it is a controversial practice that some have called cruel and lobbied for it to cease.

Officially, the reason for docking the tails of hunting dogs and other working dogs (e.g., police dogs) is to avoid injury to the tail. The theory is that it is more difficult for a wild animal or a criminal to grab onto a short tail and injure the dog. However, this explanation is suspect due to the very small number of tail injuries in working dogs with undocked tails.

The practice of docking tails appears to have originated in Ancient Rome when shepherds came to believe, for reasons that are unclear, that docking the tails of herding dogs would prevent them from getting rabies.

At one point during the 18th century, a tax was imposed on all non-working dogs, while working dogs were exempt. Then as now, there was a lot of overlap between dogs used for working and pets kept for companionship. One of the ways to tell a working dog from a non-working dog was a docked tail, so pet owners started docking the tails of non-working dogs to avoid paying the tax.

Dogs with docked tails may develop neurological conditions, which is why the practice has been banned in many countries. However, these are relatively minor, and dogs without tails are rarely at a disadvantage when socializing with their peers because they can compensate with other cues.