rabbit fever vs zoonosis

rabbit fever and zoonosis both are nouns.

Word	Noun	Adjective	Verb	Adverb
rabbit fever	Yes	No	No	No
zoonosis	Yes	No	No	No

As nouns, zoonosis is a hypernym of rabbit fever; that is, zoonosis is a word with a broader meaning than rabbit fever:

rabbit fever: a highly infectious disease of rodents (especially rabbits and squirrels) and sometimes transmitted to humans by ticks or flies or by handling infected animals
zoonosis: an animal disease that can be transmitted to humans

Other hypernyms of rabbit fever include zoonotic disease.

rabbit fever (noun)	zoonosis (noun)
a highly infectious disease of rodents (especially rabbits and squirrels) and sometimes transmitted to humans by ticks or flies or by handling infected animals	an animal disease that can be transmitted to humans