Hi guys. I could really use you guys' advice on my BC's behavior. I have had her for over a year now (she's 4 yrs old and my Aussie is 3.5 yrs old). My Aussie will go crazy when she sees other dogs (and is not allowed to play with them) and my BC will correct her by nipping her in the face. I figured this was just her correcting my other dog. I took them to a dog park last night, and my BC kept running beside my Aussie and biting her face. She seemed to not be letting the Aussie play with any other dogs, which she really wanted to do. My boyfriend and I would tell her no and pull her out of play for a minute or two, but she would go right back to biting her in the face. Side note, they play extremely well together at home and she doesn't act this away at home.
Is this normal BC behavior? Is she trying to herd her or what? Any way to keep her from biting my other dog in the face at the dog park?