I know I got him wayyyyy to early, but at the time I did not know. I was a very good mama though
As far as the shaking.... he just wants the toy. He wants it so bad that he gets fixated on it and shakes. It's riddiculous.
Example:
Yesterday my boyfriend and I were watching TV in bed and the pups were with us and Hendrix was staring at my boyfriend and shaking. After 20 minutes or so of us laughing and trying to figure out what he wanted my boyfreind realized he was sitting on Hendrix's bone...... yeah...... haha. And then when he gave Hendrix the bone he was totally fine and happy chewing his bone.