I have a six month old female shepherd. We got her when she was 8 weeks old. We have another 12 year old shepherd that would not hurt a flea. The six month old Heidi is very protective of her food. If Xtra the older dog walks near Heidi's dish Heidi will growl at her and kind of lunge. I feed them both at the same time but not real near each other. Well lately Heidi growls and lunges at Xtra if she comes around me when Heidi is by me. We always correct Heidi as soon as she growls at Xtra but it seems to do no good. When they are outside Heidi lays right by Xtra and inside she does the same. Can anybody suggest what to try to stop her nasty behavior to our older dog. I was hoping at some point down the line to get another puppy a male this time but it worries me that Heidi will not accept it. She goes to daycare once a week also so that she gets socialized with other dogs and does fine there. We got Xtra when she was 11 months old ( she had that name because she was left over and the runt of the X litter) and then got an 8 week old male shepherd. Xtra took to him right away and acted like a little mother to him. I was hoping this would be the way Heidi would respond to a puppy but now I don't know.