I'm sorry if this question has been asked before but I am at my wits end. My GSD has a severe chewing issue that I can't seem to break. He has at minimum 30 chew toys laying throughout the house and backyard at all times and if you are with him he will only chew on his bones and has no issues. As soon as you turn your back on him he starts to chew on EVERYTHING he is not supposed to. He is about a year and half old and has done this his whole life. An example of his tirade is one day while I was @ work he escaped from his cage. He had about 15 chew toys laying in the living room and he chose to chew on our new 60 inch plazma tv, our WII system and Xbox 360 and all the controllers to both systems, he chewed every power cord and cable from the tv, game systems and cable boxes, he pulled down every shade and curtain in the house, he chewed up all the throw pillows and cushions on the couch and love seat, chewed up two pairs of my girlfriends shoes, chewed the edges of our entertainment system and a couple other things but I can't remember them all right now. I have many other examples like when we left him outside one day while we went to the mall and he chewed the railing and spindles on the deck. I'd swear this dog does it on purpose because like I said if I am in an area where he can see me, no problems his bones are just fine but let me turn my back and it's the tazmanian devil. Any suggestions on how to stop this? I hate that he is going to end up spending his whole life in a crate because of all the damage he does whenever he is left alone. Any help is greatly appreciated.