prairie dog vs gnawer

prairie dog and gnawer both are nouns.

Word	Noun	Adjective	Verb	Adverb
prairie dog	Yes	No	No	No
gnawer	Yes	No	No	No

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

prairie dog: any of several rodents of North American prairies living in large complex burrows having a barking cry
gnawer: relatively small placental mammals having a single pair of constantly growing incisor teeth specialized for gnawing

Other hypernyms of prairie dog include rodent.

prairie dog (noun)	gnawer (noun)
any of several rodents of North American prairies living in large complex burrows having a barking cry	relatively small placental mammals having a single pair of constantly growing incisor teeth specialized for gnawing