Does the female boxer issue only apply with other boxers? I have a female 16 mths old and a 7 year old boston terrier. They play together (I don't allow but a couple laps around the yard and always, I side and out, have exits for the Boston as my Boxer gets too rough....just in case.Aww crap! You have basically stepped into ... serious "Deep Crap," here! Inter-Female Aggression! And Boxers are pretty much the "worst of the," worst, ni this regard!!
So your in "Deep Water," now ,,, and yep some member, "here," have been able to make multiple females work?? But ... that is not the norm???
Boxer rescues policy is "No female Boxers, will be placed in homes that already have a resident "Female Boxer!" They are that bad! So yeah pretty much the worst of the really bad in this regard!
And yep ... true to form, one year to eighteen months is pretty much right when "issues," will crop up! Muzzles are not gonna do it?? Cuz sooner or later ... you will say ... "gee everything looks good??" So I don't need the muzzle?? So you take the muzzles off?? Anr there they go again!
Males fight to "Breed," and females, fight to "Breathe!!" It's that bad!
But ... I am sigh, a never say never kinda guy myself?? ANd if you are willing to change ...uh pretty much "everything," with how you live day in and day out with these dog's??? I think that maybe possibly, you can make it work??
But other than that ... the best advice is to contact, a Boxer Rescue Rescue and Rehome the new girl! It's that bad ... sorry.
Should I be concerned about aggression? (Truble finally started her cycle at 16 mths and has been kinda mellow/less chaotic. I was hoping it meant she'd calm down a bit, my boys were never this hyper.