Boxer females fighting

Question
Have a 8 year old female boxer and a 3 year old female boxer.  Just recently the younger boxer ended her heat cycle.  In the past couple of weeks the younger boxer has become aggressive with the older boxer to the point of drawing blood while fighting.  When their are outside it doesn't seem to happen but once inside the house we have to keep them separated.  The younger one tries to get close to the older one and then they just stand staring at each other then the fight ensues...I don't know if the older boxer's health is failing and therefore the younger boxer is trying to assert herself as the "queen" so to speak.  This is the first time we have noticed this type of behavior from both dogs.  Any advice you can give would truly help.

Thanks,
Stephanie

Answer
Heat cycles can bring on aggressive behavior in females who are normally the aggressor of the two.


When she was in heat- he must have tried to mount her and dhe didn;t want to. This causes friction. She is mad because iof his persistence against her will.

The female will only accept on certain days and not the rest of the time.

When she behave this way, blow a whistle, leash her and remove her from him while verbally reprimanding her. REmover her away and keep her on her leash 5 minutes.

Soon, she will associate it to her behavoir and stop.