female sibling beagle fights

Question
I have a 9 yr old female beagle my best friend has my beagle's sister we got them at the same time now 4 yrs later my best friend passed away and I inherited her dog.  They were fine for 4 weeks but now they had a horrible fight and I don't know how to get past it. I have separated them but don't know what to do to get them back together. Please advise.

Answer
Hi, sorry for the delay and so sorry to hear about your best friend...It sounds like the beagles are trying to establish dominance in their newly formed pack. Be aware that being sisters means nothing to them, dogs do not remember these things like people do. Your female just knows she was the boss and now there is an interloper in her domain. I have a feeling because of the circumstances they were not introduced slowly and on neutral ground either.

You will need to give me more details about the fights, or has it only been one? If it has only been one time what was happening at the time? was it about food or attention from one of you? Who would you say instigated it? You will need to give me more details to try and help figure this out..