There are many different shapes for dog tails: straight, straight up, sickle, curled, or cork-screw. As with many canids, one of the primary functions of a dog’s tail is to communicate.
According to the Swiss Animal Protection Law it is forbidden to dock tails and crop ears and it is forbidden to import dogs with docked tails and cropped ears.
Further information on docking.
Picture: Legal status of dog tail docking and ear cropping by country, © Generatrisa