canid vs wild dog

canid and wild dog both are nouns.

Word	Noun	Adjective	Verb	Adverb
canid	Yes	No	No	No
wild dog	Yes	No	No	No

As nouns, wild dog is a hyponym of canid; that is, wild dog is a word with a more specific, narrower meaning than canid:

canid: any of various fissiped mammals with nonretractile claws and typically long muzzles
wild dog: any of various undomesticated mammals of the family Canidae that are thought to resemble domestic dogs as distinguished from jackals or wolves

Other hyponyms of canid include bitch, Canis familiaris, dog, domestic dog, wolf, jackal, hyaena, hyena, fox.

canid (noun)	wild dog (noun)
any of various fissiped mammals with nonretractile claws and typically long muzzles	any of various undomesticated mammals of the family Canidae that are thought to resemble domestic dogs as distinguished from jackals or wolves