A number of dog breeds are born with very short or no tails. Among them are French and English bulldogs, French pointers, Australian shepherds and Welsh corgis.
Dog breeds born with short tails or no tails have been selectively bred to have no tails. Breeders breed dogs with short or no tails until tails are mostly bred out of the population. By contrast, certain dog breeds are born with tails, but breeders dock the puppy's tails. Breeds with traditionally docked tails include boxers and pinschers. It is often desirable for working dog breeds to have no tails because the tail can collect burrs, which leads to infection. However, many modern breeders dock tails for purely aesthetic reasons.