I can't offer any real good advice. Just wanted to say I was sorry that happened. Maybe you could start off by holding him when you give him some small treats so that he will get used to it. Some dogs are just real protective of their food. Does he act out any other time?
You do know who Cassius Clay is, don't you? (I'm sure you do.) Muhhamed Ali. Maybe your Cassius wants to "float like a butterfly and sting like a bee."
(I hope you don't get upset for me making light of this. I know it is serious, but I just thought maybe you could use a smile.
)