Earthfall — Richard Alan Dickson

For generations, the Canine Cartel and the Space Cat Alliance have warred across the galaxy. While investigating an enemy signal, Cat Patrol Delta crashes on the little-known planet Earth. Delta discovers a war between cats and dogs there, too, and the cats are losing. But when the canines capture a space cat, the poor little Earth dogs may find that these space cats are a bit more than they can chew.