Big Paws Only Dog Forums

I am new to this board and hope someone can help me. I have a female 3 year old great dane. We also have 2 hunting dogs and another male great dane. The female dane has started aggressive behavior with the other dogs(especially the female). This has just started in the last couple of months. We are at our wit's end on how to solve this problem. She is great with people and kids and very affectionate with people. It is just the dogs she doesn't seem to tolerate. We have had her since she was 8 weeks old and the others were already here. There have been no changes in the household since we have gotten her. Any suggestions, I would dearly appreciate.