I have two dogs a four year old 35lb female pitbull and a 7 year old 65lb female boxer/bull mastif mix. I have had these two dogs since the pitbull was about 6 monthes old they have lived together without any issues until recently. For some reason the pitbull has started showing EXTREME agression towards the boxer. I have to keep them seperated to keep the boxer safe. When they engage the boxer does nothing other than try to get away. The pitbull has not shown any agression towards any person, she is very loving and freindly to people. I do not know what to do, I don’t want to have the pitbull put down and i don’t feel safe giving her to someone else. someone told me she is doing this because she wants to be the alpha dog now that the boxer is getting old. Any help would be very much appriciated.