My boyfriend and I each have adult alpha females who do not, will not, get along.  When we first started dating about a little over a year ago contact between the girls was strained.  Shortly after we all moved in together the aggressive behavior eventually exploded into an all-out brawl with me in the middle.  There were no serious injuries but it was pretty traumatic.  We have resorted to keeping the girls separated at all times (one secluded in the bedroom with the other out with us and after a few hours we switch).  We have tried getting them to socialize, with muzzles, but after about 20 minutes they are trying to kill each other.  

Any tips, hints, & advise will be welcomed.

Thanks. 

This may sound extreme but my daughter's friend had this problem with her dog.  She took the dog to an Agressive Dog class which did little to help.  Ellie is now on Prozac and is so much better.  She actually has a new dog in her house and after a few months they are happily cohabitating.  Moral:  talk to your vet and perhaps drugs will help.  Good luck.

I strongly disagree with putting a human on Prozac muchless a dog. By nature dogs are pack animals and when we invite them to live with us (join our pack) we can choose to let them be our pack leader or we can choose to be their pack leader. Since I do not know your pack structure before you united with your boyfriends pack, Its dificult to solve your problem. I breed and raise Chihuahuas and had the same issue you have with my females. Things aren't always smooth  but better than they were. Go to my web site and read the article Become pack leader. It might help calm down the fighting www.patz-dogs.com/alphadogtraining.html. Just remember you and boyfriend need to be alph over your dogs.

Hope this helps.