Thanks, I just read some posts about reactivity now. But how do I determine if she's reactive or dog-aggressive? Even if I'm calm (no tension on the leash, relaxed posture, etc.), she will still freak out when she sees another dog, especially a smaller one. When she sees another dog, she rushes up to it, stares at it, ears and tail erect in classic dominant posture -- then when the other dog tries to sniff her, she acts skittish and barks. If the other dog acts dominant right back, she will begin growling. She lunges, barks, growls, etc. when I try to stop her from going to the dog in the first place. Should I let her interact with another dog off-leash? I would like to see her reaction then but I don't know if I'm willing to take the risk.