Why does my cat splash water out of the bowl?

Most splashers are playing or pawing at water they find more interesting when it moves. Some are dealing with a bowl that’s too deep or too narrow for comfort and are trying to bring the water up to them. Try a heavier wide shallow bowl that’s harder to tip, set it on a washable mat and keep it filled near the top so there’s less room to splash. A fountain can satisfy a cat who clearly wants moving water. It’s a tidiness problem, not usually a medical one.