Hi Aidan, I know you have an article you recommend on this topic, but I can't seem to find it. It started with a treasure he found on a walk-was able to trade for squeaky ball-but it was the first time he growled at me. Today he did the same with a turkey neck - this was a new treat for him, he didn't have a problem with beef bones. I was able to trade him for a handful of boiled liver bits. His owner is very permissive on many levels as you may recall, even tho we have started working with a trainer. What do you think about the nothing in life is free protocol while I also work on the resource guarding? Many thanks-Jen