Both of my German Shepherd dogs have been very intelligent and have learned how to open doors with their paws without being trained to. My current dog picks up his food bowl when he is hungry or nudges the water bowl when it’s empty. As said from My Assistance Dog Inc, “They’re also incredibly sharp, observant, courageous, trainable, and loyal, which makes them the leading choice for working dogs used by the military, police, TSA, border patrol, and other law enforcement agencies”. These institutions require serious concentration and reliability and thus these dogs are essential assets to humanity. This website also discusses how they also have long history as guide dogs and assistant dogs to people with disabilities.