pug vs pug-dog

pug and pug-dog both are nouns.

Word	Noun	Adjective	Verb	Adverb
pug	Yes	No	No	No
pug-dog	Yes	No	No	No

As nouns, pug and pug-dog are synonyms defined as:

pug and pug-dog: small compact smooth-coated breed of Asiatic origin having a tightly curled tail and broad flat wrinkled muzzle

pug (noun)	pug-dog (noun)
small compact smooth-coated breed of Asiatic origin having a tightly curled tail and broad flat wrinkled muzzle	small compact smooth-coated breed of Asiatic origin having a tightly curled tail and broad flat wrinkled muzzle