Abstract: A whelping box that fits inside of a dog crate or kennel in order to prevent a mother dog from lying down on her very young puppies which can result in death of the puppies from being crushed or smothered. The whelping box is a tray-like structure which has an outwardly extending peripheral flange attached to the interior of an existing crate by the use of existing fastener bolts which secure the top and bottom half of existing crates together. The whelping box is constructed of a one piece molded plastic material that is stackable and positionable in the bottom half of an existing crate and includes an inwardly projecting peripheral flange spaced upwardly from the bottom edge of the tray-like insert and spaced upwardly from the bottom of an existing dog crate to provide a peripheral protected space for young puppies to prevent the mother dog from lying down on the puppies.