We have 3 large cats that really fling litter everywhere when they use the box.Sometimes they actually missed the box entirely. We replaced our regular large litter boxes with large, tall rubbermaid containers about 18" deep, 26 " long and 18" wide. The only litter outside is what is tracked. If they are elderly and can't jump over the edge you can cut out a lower section in the front for easier access. Once you get the floor and odor problem resolved this might hep for future issues.