I have a shih-poo who is a year old this month. Excellent little dog and very smart but I am encountering one problem. When he gets something that he is not suppose to have, he gets very aggressive and growls a lot. Has tried to bite me when I try to take something from him...I call him the junk yard dog as he will eat anything at all. Each time we have a real battle when he gets something he is not suppose to have..Any suggestions you may have would be greatly appreciated. I have to stop this behaviour asap..thanks!!