I have 4 rotts, 3 girls and 1 boy. I have owned and raised rotts for over 20 years. My 2 older females are 5 & 6 yrs and toners female is 8 months. my make is 6 months old and the must gentle laid back dog ever owned. I've never really had an aggression problem. (also all dogs are from different dams and sires). The youngest female who is already 80 pounds and as big as her older pack girls is always showing aggression towards one of the older females. There have been several vicious fights where Borte (the younger) has drawn blood and dominated the older rott. Borte, though is always submissive to me as the pack leader and obedient until she gets into a fight with Roxie. Any ideas on controlling and stopping this aggressive behavior? they really are all sweet loving dogs.