Many plastic placemats are available in at least two sizes. The size of bowl mat you need is usually dictated by the size of bowls that you use. It makes sense for both the water and food bowls to be placed on the same mat. There needs to be enough space to prevent them knocking into each other. If the bowls hang over the edge of the feeding mat, spillages will not be caught inside the lip and will end up on the floor. Some dogs are very messy eaters and will need a lot of space around the bowl.\r