Yorkies are notorious for being picky & can have off days where they won't eat too much & will pick at their food. I like to mix in healthy things they can have, foods like: diced frozen green beans (good source of fiber & since they're already cooked, they are easily digestible), cooked carrots, hard boiled egg whites, scrambled eggs.
I also had to change foods several times until they found the one they liked.
