The German Shepherd was developed from working herding dogs around 1900 as an all-around working dog. Within a few years it was clear that the dogs were losing their working ability. Schutzhund was developed at this time as a test of working ability for German Shepherds. Only German Shepherds that had passed a Schutzhund test or a herding test were allowed to breed and thus have their progeny registered as German Shepherd Dogs. This is true in Germany to this day. It is only by testing the working ability of every generation that the strong working characteristics of the GSD have been maintained. Dogs of any breed, even mixes, can compete in Schutzhund today, but the most common breeds are German Shepherds, Belgian Malinois, Boxers, Rottweilers, Dobermans, Cane Corso, Giant Schnauzers, Bouvier des Flandres, Dutch Shepherd Dogs, Beaucerons, American Bulldogs, Black Russian Terriers, Airedale Terriers, Australian Cattle Dogs, and the like.