milk sickness vs disease

milk sickness and disease both are nouns.

Word	Noun	Adjective	Verb	Adverb
milk sickness	Yes	No	No	No
disease	Yes	No	No	No

As nouns, disease is a hypernym of milk sickness; that is, disease is a word with a broader meaning than milk sickness:

milk sickness (noun)	disease (noun)
caused by consuming milk from cattle suffering from trembles	an impairment of health or a condition of abnormal functioning
disease of livestock and especially cattle poisoned by eating certain kinds of snakeroot