Okay - another quick question. We give Nina (7 1/2 months old) marrow bones, but recently, she gets angry when we even walk near her when she has her bone. One day, my husband walked by her and she growled - not the playing growl, but ANGRY. She looked like she would bite him. We can;t take the bones away from her without trying to trick her somehow, otherwise, she gets extremely possessive. Her eyes actually change and she looks like she might come at us in an unpleasant manner. This bothers me not only because it's frustrating, but because those bones are the ONLY things that she can chew on for long periods of time. I can't even begin to explain how many toys this puppy has ruined because she's such an aggressive chewer. We really have tried close to everything we have read about on this site. Not sure what else will keep her busy and deter her from chewing on things she should not be chewing on. I have read the posts re: Vaccuum behavior - we experience this too with Nina - id she's not tearing up her toys and swallowing pieces, she's eating everything on her walks, or in the yard. Geesh! I am her shadow, constantly pulling things from her mouth - and YES we watch her constantly - I will NOT leave her unsupervised for any length of time unless she's in her crate. That was longer than I hoped, but I figure more info is better than less. Thanks again!!