I have a 19 month old female who has started to start fights with certain dogs when they approach me. By the time I can tell she is going to dig into the fight mode, it is too late and she is going for it. Sometimes she is fine with a dogs approach to me and other times not. Any suggestions to defuse this? Is this a behavior thing in the young spayed females? It would be easy to say just keep her away from other dogs but that is not going to happen for various reasons. Rather I would like to help work this one out of her some how.