I have two and sometimes they can sound like they are killing each other and really they are only playing. If they start to get a high pitched growl or a growl bark combo, I will yell enough and they stop. The one that is stealing toys or showing jealousy needs to be taught to stop. My Brutus is a pain with this issue. He always wants what his brother Frankie has. I dont really allow this. Most times I can redirect with another toy or I can tell him to mind his own business and he usually does. If he wont leave Frankie alone, Brutus gets a time out in his crate. He will be let out when Frankie has had some alone time.