What kind of food do you feed your dog?

Mack is a pain in my royal ***, breed typical with sensitive skin, I started with "decent" stuff and worked my way up when after a bag it didn't work i'd try something else. Finally found something that works amazing, his coat has never been shinier, no dandruff, no balding spots. Stuff is pricey 50 for a 30lb bag. but has been well worth it.