guide dog vs working dog

guide dog and working dog both are nouns.

Word	Noun	Adjective	Verb	Adverb
guide dog	Yes	No	No	No
working dog	Yes	No	No	No

As nouns, working dog is a hypernym of guide dog; that is, working dog is a word with a broader meaning than guide dog:

guide dog: a dog trained to guide the blind
working dog: any of several breeds of usually large powerful dogs bred to work as draft animals and guard and guide dogs

guide dog (noun)	working dog (noun)
a dog trained to guide the blind	any of several breeds of usually large powerful dogs bred to work as draft animals and guard and guide dogs