Abstract: Example embodiments of the pet cooling systems disclosed herein utilize heat transfer properties of water or other fluid in a top layer for holding a supply of water. The example embodiments herein increase the heat transfer properties of the water-filled layer by adding a second layer with an additional heat transfer device that serves to extend the length of time that the water-filled layer is effective in accomplishing heat transfer from the animal laying on the layer. A first top layer is configured to receive water or some other suitable fluid that operates to transfer heat away from the animal laying on the top layer. A second bottom layer is configured to receive a heat transfer device to transfer heat from the water in the first top layer, keeping the water cooler and allowing for more efficient transfer of heat from the animal in contact with the top layer.