Our Rottweiler is agressive also. We just recentely started taking him to school with our Sib. Our teacher is great, she wants my husband to start slow, bring him in for little at a time, on the sidelines at first, but this week she wants Mark to maby bring him in the ring for a couple of minutes at a time. He seems to be doing better, this is his 3rd week. So I guess what I'm saying is;
taking her to an obedience class may help. I don't know, but that's what we're trying. Hope this helps