Make sure you learn to PROPERLY use the collar. You can't just shock the dog whenever he is bad and expect him to learn. He needs to be conditioned so eventually you won't need to use the collar. I know that you said you took him to training, but I think you really need to get the obedience down (lots and lots of repetition) in order for you and the dog to benefit from this.
American Eskimos are high energy dogs. Is he getting enough exercise everyday? You'd be surprised how much of a difference just walking the dog makes.
http://www.uwsp.edu/psych/dog/LA/castle3.htm