Is he really protective of his food? Have you tried reaching down to move his food dish while he's eating? I think behaviorists do this to see how aggressive they are. I think if you can easily take their food away from them, they're not seen as aggressive.
I love Victoria Stilwell! That show is so great. I've learned a lot from both her and Cesar Milan -- and I've been around dogs my entire life.
What??? I've never heard such nonsense about the Gentle Leader. It's a walking tool, and yes, it can be used for other purposes like a dog who jumps or lunges. But no tool will take the place of a firm presence. I have an aggressive dog (one MUCH bigger than a JRT), and I would never in a million years rely on a Gentle Leader for anything more than having more control while walking her.
Yep...my feeling as well. It prevents them from pulling, not showing them who is 'the boss'. My dog knows who's the boss....we've had this 'discussion' several times in his 8 yrs...sometimes he forgets and I have to remind him!!! But, he knows who the alpha is in our house.
Dogs sense any hesitancy on the part of their owner. Then, they think they've taken over. You're hesitant, the dog 'wins' so to speak. He has imposed his will on you...plain and simple.
Get help from a professional. It's hard to rescue a dog because we have no idea what his 'baggage' is. And all the good intentions won't help us if we don't understand that baggage. Besides, a dog is a dog, not a human. They have a vastly different way of looking at life. Most things are instinctual in them. Shelties work keeping track of herds of sheep. They nip at those bad sheep that leave the pack.....it's the dogs job to nip and snap. So, put that dog into a situation where he may feel it's the right thing to do, based on his 'job description' as a breed, and you could have an issue. But, that doesn't mean he isn't going to be able to relearn stuff. It just takes a firm hand and some outside help.
A short story...we were looking for a new puppy. We found a breeder who had good credentials, was showing her dogs, she was doing everything you would want a dog breeder to be doing. So, we asked for a nice female golden this time...had been down the road with the males and really wanted a smaller, more biddable dog. Well, the breeder called me to tell me the litter had been been 'typed' so to speak, and they had the perfect dog for us. Only thing was that it was a male. The breeder told me that she had a female we could have but she really thought we were the right family for this male. Seems he tested as being somewhat stubborn and independent. She figured that I had been down that road and she felt that I could handle a bit more foreceful pup than someone else. Well, we took him, he's a wonderful dog, but man, is he stubborn. Not sure why he sometimes thinks he's gonna win the battle, but he tries to get away with it. Never works for him. I remind him....he's the dog, I'm the pack leader...he's the brave, I'm the chief...I hand out the food, he eats it.
You have to understand where the dog is coming from. Then you can work with him, so that both your family and the dog are happy. There is nothing better than a well socialized dog within a happy family. It's just so darn American and Normal Rockwell!!!