Livestock-guarding dogs Certain breeds of dogs have been used for centuries to protect livestock from predators. The practice of using guard dogs originated in Europe, and American ranchers have used guard dogs since the mid-70s. While the duties of European guard dogs have included protecting livestock against wolves and bears, guard dogs in the U.S. have most often been used to protect sheep from coyotes and smaller predators. Guard dogs tend to be more effective with sheep than with cattle because the sheep stay closer to one another. Cattle are more solitary, especially in the West, where they roam over immense areas in search of food and water.
Dogs also bond more readily with sheep than with cattle.
Guard dogs usually do not have the herding instinct typical of herding dogs, but when properly bonded with livestock they exhibit a strong protective instinct. They protect their charges by scent-marking pastures, barking, and chasing predators that actually threaten the sheep. Ranchers have had mixed results using guard dogs to protect against wolves. Some have claimed significant success, while others have had dogs killed by wolf packs or hungry lone wolves intent upon reaching livestock. It is likely that guard dogs offer the best protection where wolf density is low and multiple dogs guard a relatively small area.