We have had some success in dealing with his separation anxiety because we were given permission to use kongs stuffed with peanut butter (or moistened dog food). He LOVES them. In fact, today, as I walked in Fred had just shut him up in the crate with a kong stuffed with kibble. Jam complained until I opened the crate door and then he stayed in the crate with the door open while he tried to take the kibble out of the kong.
He can be a weird dude.
But one of the more charming things he does is when he is through with his meal. He's never, ever, really satisfied with what he has received.
Honestly, his name should be Oliver.
Well, you watch and decide.