my almost 18 month old boxer, Tyson

Question
Hello, we recently as of August welcomed Tyson into our home; consisting of myself, my 3yr old son and my 9yr old daughter. The woman I purchased Tyson from assured me he was excellent with children as she had two small grandchildren who played with him constantly.  At first everything was fine, yet he would have accidents in the home and when scolded acted super-submissive making me feel he might have been abused or unnecessarily punished. He has been wonderful with the kids until recently he's become a little over-protective with me and my son, to the point where he actually growls and has nipped my daughter when I've been play-fighting with her. He looks at her strange and worries me constantly that he would hurt her. He's already 85lbs and my daughter's 60lbs is no match for him...help me please I love my Tyson, but could never forgive myself if something happened! I just want him to warm up to her...do you think it's possible?

Answer
You've practically diagnosed it yourself: you said he is protective of you and your son--- and when you "play fight" with your daughter, he sees her as the aggressor to you (and your son) and will defend you both...

Boxers may love all family members, however, if one family member is aggressive to another, he will go after an aggressor to protect the "victim."

I highly suggest not to "play fight" with your daughter or any children anymore.

If you must have these play sessions, Tyson needs to go into the back yard during this playing.

Remember, Boxers may love the entire family-- but will protect the victims against any family member that is aggressive.....

You need to get control of this with calm behavior, calm playing, and your children need to not fight either.