i have 2 with tails they are the ones i bred and 2 with out but they were done b4 i got them, brandis tail is done badly and is way to short with a bone sticking out the end
it use to be done when yorkies were used for ratting and was to prevent injury, but now its just done for the look of it ie breed standard. some people tie cord around the tail or a band and cut the blood off so the tail dies and drops off, but most have a vet do it, he uses a tool that looks kind of like a dog nail clipper and cuts the tail off. pups do cry when its done, in the uk its illegal for someone to do it and only vets can do it but it will soon be illegal for them to do it too as in the uk its seen as cruelty and it is not needed anymore as the dogs are not working dogs anymore.