German police dog vs sheepdog

German police dog and sheepdog both are nouns.

Word	Noun	Adjective	Verb	Adverb
German police dog	Yes	No	No	No
sheepdog	Yes	No	No	No

As nouns, sheepdog is a hypernym of German police dog; that is, sheepdog is a word with a broader meaning than German police dog:

German police dog: breed of large shepherd dogs used in police work and as a guide for the blind
sheepdog: any of various usually long-haired breeds of dog reared to herd and guard sheep

Other hypernyms of German police dog include sheep dog, shepherd dog.

German police dog (noun)	sheepdog (noun)
breed of large shepherd dogs used in police work and as a guide for the blind	any of various usually long-haired breeds of dog reared to herd and guard sheep