Dogs don't realize that we humans find it disgusting when they drink fresh water from a home toilet. Still it is their drink of choice. Even kitty likes the coolness of the lavatory, and porcelain is the dog or cats preferred material when it comes to drinking water in a nice cool basin. That is, they prefer a deep porcelain bowl that maintains cold to cool aerated water, better known as the toilet,commode,or some other French word. They know from just sniffing the water bowl whether or not you have lately provided fresh water. Dogs do not like the taste of water that has stagnated and picked up the taste of plastic,etc. In this case, your dog may turn to the toilet. Your cat may run away from home.