Prey drive is just one of those things I don't think you can train them out of. my dogs have always been very trustworthy with my cat indoors. But I caught them once chasing him outdoors, he went into their kennel, and I was really afraid they were going to hurt him. The huskies do kill loose animals all the time, mostly squirrels and rabbits, but fortunately no cats to date. Keeping a leash on them is really the only way to stop them if they start to chase something. Recall just doesn't work. Poor kitty