What about a lightly scrambled egg (in butter - not margarine), try i raw first and if won't eat it then scramble or some coconut oil, sardines. He is probably hooked on the sugar and rendered fats in kibble.
and of course tripe - good and stinky b/c dogs eat with their nose
He is your friend, your partner, your defender, your dog. You are his life, his love, his leader. He will be yours, faithful and true, to the last beat of his heart. You owe it to him to be worthy of such devotion. - Unknown