See, despite the fact that this seems a contradiction (cats, after all, are preditors with each of those species on their "shopping" list), I understand that. It is possible to keep such conflicts of interest as it were under control. Dogs, for example, are another preditor, and we keep them because they are very helpful on the Ranch and also fun to have around. But we can not tolerate a dog that starts killing livestock. If we've got time and control, we'll find another home for the dog. Otherwise, there's a very difficult choice to be made.