fighting danes

Question
I have two great danes, mother and daughter. I had the daughter first and she is almost two years old, then I got the mother whom is about 4 years old. The mother is spayed, but the daughter is not, and she is currently in heat. They have always gotten along, until lately. In the past three weeks they have broke out into viscious fights. Of course I thinking of a whim got in the middle, both times, which has resulted in stitches. I love these dogs and don't want to get rid of either of them. Could they be fighting because one is in heat or what could be the problem. After the first fight we separated them and when they were together watched them very closely and them seemed to get along as usual, so I let them back together on a regular basis. The other night they broke out into a fight again. They aren't playing with toys or eating when this happens, both times they were laying on the floor together and they just suddenly fight. Any help would be greatly appreciated.

Answer
You know what they say about two women in the same house!  Bitches fight worse than dogs and often cannot be left together.  The youngster is showing her dominance over her mother so I suspect you will never get them to live harmoniously together again.

If you ever got the youngster in whelp she could kill her mother.

Ken