The Australian Cattle Dog (ACD), or simply Cattle Dog, is a breed of herding dog originally developed in Australia for droving cattle over long distances across rough terrain. This breed is a medium-sized, short-coated dog that occurs in two main colour forms. It has either brown or black hair distributed fairly evenly through a white coat, which gives the appearance of a 'red' or 'blue' dog. Australian Cattle Dogs have been successful in a range of dog sports including weight pulling, flyball and schutzhund. The breed is particularly suited to activities that a dog can share with its owner such as canicross, disc dog, and skijoring or bikejoring. It is an effective hiking companion because of its natural endurance, its general lack of interest in hunting, and preference for staying by its owner's side. The Kelpie breed was developed after the Cattle Dog type was described, so its infusion is unlikely.