Bruiser is 14 months old, and has NEVER displayed any kind of agressive or assertive behavior besides insisting on being the center of attenion. Yesterday he was eating a treat. It was a large rawhide chew. Normally I do not give him these, but he left the vet's office with it in a bag. He knew it was there and very much wanted it. He had one and Bama, 17 weeks old, had another. First of all he would not let Bama have hers. He would drop his and take hers. I would just give her the one he dropped. This "take away happened several times until Bama lost interest in either chew. They played fine for another hour, then as Bama started to play, basically on Bruiser's head he gave a growl-bark(a serious one). It was definitely directed towards Bama. She shrugged it off and went on her way. I decided enough was enough with the rawhide so I tried to take it away from Bruiser. He knew what I was about to do and took off. When I restrained him and reached for his mouth he growled at me. I don't tolerate that kind of behavior. I took his face in my hands, told him no, and gave him a long hard stare. Then in a much softer tone I coaxed him into letting go of the rawhide, which he did looking a little ashamed of himself.
OK, What did I do wrong/right, and what can I do to ensure that this type of behavior does not Adminse again.
Let me say again that Bruiser is normally not aggressive with treats, toys, or food. I ususally can and do reach in his food bowl, reach in his mouth to take things out, and he has never been mean to Bama in any way. As a matter of fact in the beginning I thought Bama would be the dominant dog. He normally lets her chew on his nylabone's and kong's even when he is chewing on them. Thanks