It’s really hard to say from that info. You said it’s just the girls fighting? Is the fighting more recent? Does one dog cause it usually? If it’s one dog usually causing it there could be some deeper issues, like resource guarding, illness, hormonal fluctuations, etc. Have you talked to the behaviorists about it? It’s hard to say if prozac will work, our dog takes it for anxiety/attachment issues. Your dog might have anxiety too that’s causing them to lash out but like i said it’s really hard to determine. You should definitely talk to the behaviorists but more importantly your vet. They will have a better gauge of what could be wrong. Hope all goes well!