work animal vs animate being

work animal and animate being both are nouns.

Word	Noun	Adjective	Verb	Adverb
work animal	Yes	No	No	No
animate being	Yes	No	No	No

As nouns, animate being is a hypernym of work animal; that is, animate being is a word with a broader meaning than work animal:

Other hypernyms of work animal include animal, beast, brute, creature, fauna.

work animal (noun)	animate being (noun)
an animal trained for and used for heavy labor	a living organism characterized by voluntary movement