Maggie was like that too. Then came yesterday!!!! This time she ran to the fence and barked, before the 5 big dogs next door got the first bark in. It was so funny, because the neighbor's dogs just stood there in shock.
I picked her up immediately before the dogs knew who was chewing their butts out. A couple months ago, she would cowl down to be submissive to bigger dogs. Guess no more!!! I got a 4 pound dog with a 400 lb. attitude.