German police dog vs German shepherd

German police dog and German shepherd both are nouns.

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

As nouns, German police dog and German shepherd are synonyms defined as:

German police dog and German shepherd: breed of large shepherd dogs used in police work and as a guide for the blind

Other synonyms of German police dog include alsatian, German shepherd dog.

German police dog (noun)	German shepherd (noun)
breed of large shepherd dogs used in police work and as a guide for the blind	breed of large shepherd dogs used in police work and as a guide for the blind