A police dog is a dog that is taught specially to assist police and similar law-enforcement personnel with their work. They are also known in the United States as police K9s
The term is occasionally used in the common parlance of several countries to refer to any German Shepherd Dog because of the long history of the use of the German Shepherd by the police and military; in some nations German Shepherds are the only dogs used by those forces. In the post-industrial era German Shepherds have often been depicted as police dogs in television, movies and police dog memorials. This breed is often still used, as are a few other breeds.