you are moving it on to fast - you need to do the yours and mine to fluency - until you can put the bone/ear on the floor at your feet and let it go and still do the mine yoursby allowing him to have one on his own like this then you are setting him up for an extinction - you are teaching him that he doesnt growl when you are holding - giving etc but he can at other times there is a vid on here somewhere with me doing this with nacho - mudge's weim - except we both on the floor and we are passing a lamb bone mouth to mouth...you have to build it up slowly and not allow the dog to break the cue at each stage you are at - you have to get fluency through the criterias