Is it a good idea to try take the ear at all, I wonder? I wonder if it would be better to just give him half an ear, or something he can finish within 15 mins etc. or whatever time is going to be ok for you. Start by just being able to approach the ear and drop him a super treat, until he is happy to have hands round him when he is eating an ear, but don't try to take it. Sort of the same steps as for a food bowl, but for the ear. My dog will sometimes give me items he views as food, but doesn't resource guard at all, and I have never done anything with a food item but return it to him, only saving not giving it him back for things he picks up outside that might be dangerous. Even then, I cannot say that I have a reliable cue for my dog giving me food that he already has in his mouth - I think this is really very difficult to train, although I've managed it in the house, and pretty much impossible to proof. http://www.thelabradorsite.com/how-to-stop-your-dog-growling-over-food/
You mean you can't get Charlie to hold a hotdog in his mouth like Nando Brown's Fizz? I agree that I don't want my dogs to feel I'm ever going to take good things away from them. I've never had to deal with a dog who resource guards, though. I think using a non-food item to reinforce the "I take it, you get a treat, I give it straight back to you" is a good trust exercise and a reinforcing behaviour that can be utilised when you do have to takes something away from him. You might also find that as time goes on, the ears lose their novelty and he becomes less possessive of them naturally. I would like to reach the stage with my "give" that my dogs would relinquish an ear, a tripe stick etc on cue.... but that's a little way off. Just a little.
I just think swapping a kong, a chew etc. with a tasty treat from a dog that doesn't resource guard, is not the same as dealing with a puppy that is already growling over an ear. If I had any signs of resource guarding (which I don't), I'd be working through it step by step, and I wouldn't start by removing the food no matter what I was swapping it for. Just my thoughts, anyway.
