pooch vs Canis familiaris

pooch and Canis familiaris both are nouns.

Word	Noun	Adjective	Verb	Adverb
pooch	Yes	No	Yes	No
Canis familiaris	Yes	No	No	No

As nouns, Canis familiaris is a hypernym of pooch; that is, Canis familiaris is a word with a broader meaning than pooch:

pooch: informal terms for dogs
Canis familiaris: a member of the genus Canis (probably descended from the common wolf) that has been domesticated by man since prehistoric times; occurs in many breeds

Other hypernyms of pooch include dog, domestic dog.

pooch (noun)	Canis familiaris (noun)
informal terms for dogs	a member of the genus Canis (probably descended from the common wolf) that has been domesticated by man since prehistoric times; occurs in many breeds

pooch (verb)	Canis familiaris (verb)
round one's lips as if intending to kiss