Recently I agreed to train an 8-month old Border Collie for a woman who has been in and out of the hospital. Her basics have been going fabulously. I'm almost done training her already. She's very smart but easily distracted, and if you completely lose her focus then it is VERY difficult to get it back. She's getting better and I'm not worried about that....but..... She has a very, very, very severe dog herding issue. She lives with an Aussie, another female. When the two of them get excited and playful, she bites at the Aussie's rump, just above the tail...so much so that her rump is permenately soggy and almost matted. The Aussie has so much hair that she doesn't feel it, and she does nothing about it. I can't work with these two together because the Aussie had a terrible trainer and is extremely protective of her owners. The first time I went over I was very concerned with my own safety. I could get her to calm down and sit on command a few times, but she was still very agitated and aggressive. Outside of the home she is an entirely different dog, very friendly and calm. The husband of the household stood by while she was almost attacking me and did nothing. This bothers me for very obvious reasons.... The severity of her issue doesn't come out as much with her Aussie roommate, because they know each other and know their limits....but with dogs in general, she's an uncontrolled stock dog. I know that this is quite common in Border Collies and many other herding breeds, but I've never had one as bad as she is. But as for Misty, the one with the herding problem, I can't even keep her with my own dogs because I'm still working on Rusty's dog aggression and Zeke and Mudflap would definitely put her in her place if she attacked their rears...I know that all I have to do to get them to calm down and ignore her is a sharp, "Ah!" but Misty isn't near as controlled. She's never had any training so she's not familiar with this, and the "Ah!"s do nothing for her. I worry that the time between the loss of her focus and regaining it back could be enough to reinforce the bad behavior. I've worked with dog herders before but she is by far the worst. If she did this to my dogs, and they defended themselves...and she did the same, I don't know what to expect from her. And I can't call her off. Rusty loved her initially and he's been doing great, but I don't want her herding behavior to set his progress back because he feels he needs to defend himself. Tonight we had a near incident. Mud was in the backyard and Misty slipped out, and since Mud was running and playing...she immediately went into herd mode. Mud growled a little at the unexpected sneak attack and I called her in right then, so she came running in with Misty right at her side nipping. I caught Misty and let Mud slip in, but if Mud hadn't had such good recall and self control, we would've had a situation on our hands. She enjoys the company of other dogs, so it's not an aggression problem. She loves having playmates, but her manners are ridiculous and the herding will get her in BIG trouble someday. Any suggestions are very appreciated.