My Aussie Is Aggressive Towards Strangers
I have a female Aussie named Sibyl. She's three years old now. I got her at ten months. She is spayed. We live on a big chunk of property, but it has a subdivision quality, so we get joggers and baby carriages and such traffic.
She's an inside dog mostly. It's a family home with my mother, her sister, me—a middle aged male, my cousin— a young woman, and her two toddlers. She's a part of the family and she loves all of us, but she's very protective of the property and the kids.
She takes off running towards people when she sees them on the street, barking and being aggressive. She's bitten numerous friends who visit. She also nips people that she's generally accepted, but that's a herding/dominance issue. She gets along fine with other dogs (as long as the children aren't afraid) and she usually gives kids a pass.
She knows I'm the alpha. She's very obedient. She doesn't get enough exercise, though that will change now that the weather is warming up. I socialized her when she was young, and she wasn't standoffish with anybody then.
She seems to have developed this aggression in the course of the past year or so. We're having an underground fence installed to keep her contained, but I want to get at the root of the behavior. It's become a real anxiety. Giving her up is not an option, but neither is continuing with this behavior.
Any advice is appreciated. Thanks!