The title is pretty self-explanatory but to give some more detail, he is a bit over a year old rescue. I do mix it up every day and he does eat it happily. When he came to us he was very quiet and we actually thought he was mute. He has become pretty vocal now esp. when someone is eating. At first i ignored it and just gave it to him but now I've started to wait until he becomes quiet before giving it to him and taking it away if he hisses or growls at me. Am I doing it wrong, is he actually scared/in pain or is it just a learned thing he does that can be trained away?