What worked for me and Jake (Australian Shepherd X Border Collie mix) was to just ignore the cats. Jake loves to chase them when they move, obviously because of his breeding, but I've learned that he seems to pick up on a cues from me. If I pay attention to the cats, he will too, but if I act like I've got better things to do, he'll ignore them. He hurt his paw a couple of weeks ago, and I've taken advantage of his "handicap" to work some more on teaching him to leave the cats alone. On the first few days, Jake was too busy licking his paw to pay attention the cats, and the cats both figured out that that meant he wasn't going to chase them. So they got braver and crept in closer, and if Jake noticed, he usually just stared at them. Willow's got a way of intimidating Jake, so if it's Willow watching him, Jake will drop his eyes and lay his head down on the ground. Right now, both Jake and Willow are getting along beautifully, but Willow is still prone to panic attacks if Jake makes a sudden movement/sound (she may be sleeping, but if Jake picks up his ball and bounces it, Willow will wake up and stare at him with huge, buggy eyes).
On the other hand, we still have some convincing to do with Buffy. She's not convinced that Jake has been turned around, so if he comes into view, she won't let him out of his sight. But, luckily, before Jake hurt his paw, I was teaching him that whenever Buffy growls or yowls at him, he has to back off by either backing up, lying down, or doing something else. It seems to be working, but I still need to reinforce the commands (the teachings are still pretty new, so he hasn't quite got it in his head that the funny sounds from Buffy mean that he has to back up). But at least he isn't charging forward and chasing her, which is a start. And all 3 will sleep in a room together quite peacefully, with even Buffy feeling safe and calm. It's just when Buffy is concious and uncomfortable when "accidents" can happen. But as long as I'm around, I can divert each of them, preventing anyone from going backwards in training (if Jake is doing the Border Collie stare on Buffy, for example, I just have to say "Here!" or "Jakey go 'round!" which means for him to drop his eyes and go around to the next room or something). But when Buffy's not growling or putting up a fuss, Jake doesn't see her as very interesting, and he'll do his own thing (playing with a ball or sleeping, the latter being Buffy's preference, lol)