The German Shepherd (German: Deutscher Schäferhund, German pronunciation: ) is a breed of medium to large-sized working dog that originated in Germany. They can become overprotective of their family and territory, especially if not socialized correctly. German Shepherds are highly intelligent and obedient, as well as protective of their owners. German Shepherds are a popular selection for use as working dogs. They are known for being easy to train and good for performing tasks and following instructions. A number of these dogs were taken home by foreign servicemen, who were impressed by their intelligence. Currently, Labradors and Golden Retrievers are more widely used for this work, although there are still German Shepherds being trained. In 2013, about 15% of the dogs trained by Guide Dogs of America are German Shepherds, while the remainder are Labrador Retrievers and Golden Retrievers.