Expert: Jill Connor, Ph.D. - 10/3/2008

Question
I have 4 dogs in my house, a 3 year old German shepard mix, a 2 year yorky/poodle mix, a 12 year old pit and a 18 month old boxer/bull mastiff mix.  The boxer mix is the last one to come to my home, all the other dogs get along and he was fine for the first 2 months, the shepard mix is neutered, the pit is spayed, everyone seemed to know there place and then suddenly the boxer starting fighting with the shepherd and the fights are very vicious,  now have to keep the other 3 dogs separated from the boxer.  He also went after the pit several days ago, but the main concern is his aggression with the other male dog, I don't understand while they all lived together in harmony for over 2 months that this problem would now arise.  When the boxer was first introduced to the others there was a few times the 2 went at it but then it seemed like the boxer took his place and the shepherd was the male alfa. I am also concerned about my 9 year old son with the aggression being shown by the boxer.  Also the boxer came from an abused owner and was kept locked in a basement until I took him.  Any help would be greatly appreciated.

Answer
This is a complex situation requiring the in person evaluation of each dog separately, observation of the "pack" together, in depth interview with all humans involved, and assessment of the Boxer's level of socialization with humans and other dogs.  This is NOT a question anyone can answer online.  You need to locate a certified applied animal behaviorist; in fact, you should have done so when this problem first erupted.  Your Boxer has had little or no socialization at all to other dogs and most likely humans as well, ESPECIALLY CHILDREN.  Under NO circumstances can you allow this situation to develop any further!  Contact the veterinary college in your geographical area and ask for referral to a bona fide behaviorist.  DO NOT bring in a dog trainer, this will make it far worse.  One cannot attribute "pack" behavior to a household of dogs whose human companion (you) is not educated regarding how to obtain the so-called "alpha" position YOURSELF.  This is not in any way your fault.  As I wouldn't be able to do YOUR job, you naturally can't do mine.  Please locate an expert ASAP.