I have a purebred male sheppard almost six months old. He will be neutered on July 18th. He is very strong-willed and difficult to control. He puts EVERYTHING in his mouth and chews on it. He will destroy it if left alone. He takes stuff off tables and counters, out of trash cans, and anywhere he can find it. He is almost always around his owners. If we leave the house he goes in a crate, which he likes. Nothing is safe. How do I stop this??