Boxer aggressive towards unknown dogs

Question
Hello, I have a 20 month old female boxer that is the most playful/loving dog with all people, kids, familiar dogs (a small few the she plays with regularly) and our cat. BUT, when I take her on a walk, to the dog park or vet around dogs she does not know, she gets aggressive. She doesn't really bite the dog, but growls, barks and "boxes". Other people with dogs get scared even though I know she won't bite another dog. How do I break this? She does it mostly on a lease and it all started when she went into here first heat about 6 months ago. I had he spayed after her heat, but there was no change. (PS. she is the Alpha dog whenever she is around the dogs she knows)
Help please. Thanks!

Answer
Dear Elijah,
Thanks for the question. Inter-dog aggression and leash aggression are complex issues. People have written books about the subject. Here are some tips and resources for detailed information.

Your goal is to get her to perform a behavior (like sitting and looking at you) that makes it impossible for her to focus on the other dogs. First you should teach her to sit and relax when other dogs are not nearby.

Once she can do this you can start working with other dogs in sight, but not so close that she starts barking and lunging.

Practice these exercises over and over and slowly move closer and closer to the other dogs during several sessions.
Give her treats and rewards for sitting.

I'm guessing you've tried fussing at her and correcting her when she behaves aggressively. That won't work! (smile)
If she fails to sit, don't correct her, just move farther away.

There are some good books with specific instructions. 've listed them in order of my preference. -
FEISTY FIDO: HELP FOR THE LEASH AGGRESSIVE DOG
by Patricia McConnell & Karen London

Fight! (Paperback)
by Jean Donaldson

Check out these books and get started on rehab for your dog!

Happy Training!
AT

http://www.howsbentley.com