I NEED HELP!!!!!! a cushings case!!!?

my grandpa owns a mule with cushings (haha i know a mule:)) anyways he is going downhill very fast and could possibly die, he is stubern like the mule that he is and he wont take his medications! he is getting worse and worse with muscle loss...ect. soo im wondering if you know anyway to get a mule to take his medications, mabeye like mix it with somthing...idk, please help:/ if it helps his medicine is a powder