YOU SAID:
My cow was very sick so I gave it medicine for the sickness
INTO JAPANESE
私の牛がとても病気だったので、病気の薬を与えました
BACK INTO ENGLISH
My cow was very sick so I gave her medicine for the disease
INTO JAPANESE
私の牛は非常に病気だったので、病気の薬を与えました
BACK INTO ENGLISH
My cow was very sick so I gave her sick medicine
INTO JAPANESE
私の牛は非常に病気だったので、病気の薬を与えました
BACK INTO ENGLISH
My cow was very sick so I gave her sick medicine
That didn't even make that much sense in English.