sounds like the beginings of food aggression. try to nip that in the bud now before it gets out of control. they say to stop free feeding when they start showing that behavior. also with treats and bones hold them while he is chewing them, take it from him and if he is fine and doesn't snap or growl say good boy and let him have it back, if he snaps and growls don't let him have it back. helps. when you feed him his meals feed him only after you ate your dinner (it helps show who is alpha when he has to eat last) also feeding him a few pieces of food by hand helps. if he goes after another animal while eating take his food from him and let him kow it's unacceptable behavior. some rescue's will put an animal to sleep because of food aggression (not saying chico will ever end up in a rescue don't get me wrong just trying to state how serious food aggression can be.) even if the naimal has the best disposition ever and never snaps any other time exept when it comes to the food, they will euthanize it. (and i'm not saying he should be put to sleep because of it either)
the problem with food aggression is it starts leading to possesivness. if he grabs something that he shouldn't have that had fallen and you try to take it away that possesivness and food aggression sets in and you get bit badley.
a friend had a basenji and it jumped on the table and snatched a block of bakers chocolate and he tried to take it from him and got bit real badly (needed 4 stitches in his finger). the dog had to be admitted to the hospital and almost died from eating the chocolate