It sounds like your getting good advise here. A behaviourist would help, but like someone said herding dogs do nip. My girls get herded all the time at the dog park by a border collie there. And even though my dogs are deemed cat safe and ignore mine in the house, outside it's a different story, if something runs outside..they're going to chase it and there is hardly anything that can out-run a Greyhound, fortunatly they have'nt killed anything. I wish you luck with Pandy.