In a 3-2 decision Thursday, the justices ruled that the felines were a distraction and interfered with driver Patricia Edwards' ability to see where she was going.
Chief Justice David Gilbertson said Edwards nearly backed into patrol car at a convenience store parking lot in Pierre, S.D., because of the moggies in her back window.
The court said Edwards and her cats presented a significant risk to the public.
Edwards was appealing a lower court ruling that transferred ownership of the cats to a humane society for adoption.
