The initial fight I only heard because I was behind the fence with my horse. I heard the fighting, much different then their play noise. I had to physically keep the puppy from jumping back into the fight and she was circling and trying to get back at him while growling. Later that evening, we tried to put them together again and she growled and jumped at him like to try to fight. Same thing this morning, he wanted to play, then she went stiff, growled and I grabbed him before she could jump him.