over protective boxer

Question
I have an 11 month old female boxer who has become very over protective of me and my family. She will try to bite anyone who comes into our home that she doesn't know. I try to get her used to unknown people by putting her leash on her and keeping her just far enough away from them that she can't jump on them. She has actually bit three people already. We really love her but don't know what to do. Is she too old to be trained?  I don't want to have to keep her put up or get rid of her.

Answer
She should have been socialized from the moment you got her.

She has become the age that territorial instincts have taken over, and since she wasn't properly socialized by training her what was acceptable and what was not acceptable- she is reacting to her instincts to protect and distrust others.

Using the leash, introduce her to a friend visiting. When she becomes aggressive; growls, etc., verbally reprimand her and move her to a crate or shut off room for 5 minutes max.

Then, bring her back out on her leash and try again.

Be consistent with your verbal reprimands and timing.

If this does not work quickly-- buy a clicker or a whistle and use it when she becomes aggressive and verbally reprimand her and remove her and introduce her back again. The sound of the clicker or whistle will become a symbol of obedience; that she is doing something unacceptable.

Give her a treat when you bring her back in to let her know everything is alright and associate a treat with good behavior.