[Wolfiesmom]

I don't know what has gotten into him today. This morning, he was chewing a bone int he diningroom, when I heard him break off a piece. I went over to him, and checked his mouth for the piece of bone that splintered off, and reached down to take the bone away. I
He growled at me when I tried to take the bone. I took him by the collar, moved him away from the bone and then took the bone and threw it away.
Tonight, he stole a piece of plastic, and ran under the diningroom table with it. I went after him, and went to take it away. This time he showed his teeth, growled, and put his mouth on my wrist. He didn't bite, but just put his mouth on me. I put him in his crate for a time out.
He has never acted like this before. I have never had any troubles taking anything away from him ever.
What can be triggering this new behavior, and how do I remedy it? Wolfie has always been a sweet boy.