fistula vs fistulous withers

fistula and fistulous withers both are nouns.

Word	Noun	Adjective	Verb	Adverb
fistula	Yes	No	No	No
fistulous withers	Yes	No	No	No

As nouns, fistula and fistulous withers are synonyms defined as:

fistula and fistulous withers: a chronic inflammation of the withers of a horse

fistula (noun)	fistulous withers (noun)
an abnormal passage leading from a suppurating cavity to the body surface	a chronic inflammation of the withers of a horse
a chronic inflammation of the withers of a horse