Imagine if I gave you $1 and then tried to take it away from you. How hard would you resist?
Now imagine I gave you $1,000? NOW how hard would you resist when I tried to take it from you?
That's the difference to Zach. The bone is MUCH more valuable and he wants to keep it.
I prefer to train my dogs to allow me to take ANYTHING they have instead of ignoring the issue - just in case one of them picks up something I don't want them to have.
Here's a link to my page on dealing with food aggression:
How to Deal with Food Guarding from the Raw Dog Ranch