My Male Boxers Agression

Question
I have a 3yr. old male boxer. He used to be great and playful with all dogs and people, but apx 2 years ago he was playing with a neighbors pitbull/boxer breed and the other dog attacked him. Ever since he is very aggressive with other dogs. We also have a 5lb female Chihuahua and 2 male cats. The boxer is best friends with our Chihuahua and is OK with the cats, but he is aggressive to anyone walking by and all dogs. He tries to break through the door everytime another dog walks past and has broke through the door a few times and attacked other dogs. I am afraid that one of these days he will get out and really hurt another animal. So far everytime it has happened he has not harmed the other animals he has just held them down and showed he was boss. I am in fear that one day he will hurt them. He also occasionally gets aggressive toward family members in the house and the other animals. What do I do, how can I prevent this behavior. I can't even walk him or take him to the park to run because I can't trust him. Another neighbor of mine went through the same behavior with her boxer and the city made her remove him from her house and forbid the dog from coming back into our city. I want to stop this behavior before the city does the same to us. Please Help we are desperate.

Answer
That early event when he was 1 year old, has caused him to distrust other dogs. He is protecting the family and the other animals in the house. It's his job-- he thinks.

Now that he does not trust other dogs, he has become a protector.


I always tell people to use a whistle.

So, buy a loud, obnoxious sounding whistle.

Each and every time he growls or acts aggressive, blow the whistle numerous times, grab him up and leash him. Verbally reprimand him in a stern voice (no shouting, screaming or cursing though) and use simple and easy to understand commands/terms.

Maybe since it's toward other dogs, tell him, "No-- bad. FRIENDS. (say friends in a nice voice)-- Bad boy. No! FRIENDS-- It's okay--- FRIENDS!"

The verbal choice of words and the tone of your voice sets the future success or failure.

All the words are stern. The telling him they are "friends" is nicer and he will soon associate the word "friends and okay" with being approved by you.

The sound of the whistle (use it with all your behavior modifications with him) will associate his bad behavior to your reprimand to stop.

Soon, when he hears the whistle, he'll stop in his tracks.

Have everyone in the family do this each and every time he misbehaves in any way.

Get it under control before the city removes him. If they visit you about him, you can at least show you are involved in behavior modification currently.