How to build a whelping crate for your Mastiff or any other size of dog. You can determine what size whelping box you need by making sure your dog has enough room to walk around the whelping box. The purpose of the whelping box is to make sure that the mother does not trap one of the pups between her and the box, and squeeze them to death.

The English Mastiff, or any other large dog, can easily calm their pups if they pounce on them. The way I made my whelping crate for my Mastiff was I took a full sheet of 1/2 inch plywood and cut it in half. The floor was now a 4 x 4 piece, and I used 2 x 2 lumber to frame the inside and along the edges for a nice look. I took 6-inch wide PVC pipe that you can buy at any hardware store, cut 6-inch pieces of the PVC, and used them for the legs on the inside. I used plastic PVC elbows to connect them into a perfect 4 foot square that I could get up and down quite easily in the whelping box.

When you have the PVC plastic pipe inside the box, it makes it more difficult for the mother to lie against the sides of the box, when she is feeding her pups, and if one gets stuck behind her when she moves around all the time, it gives the pup an extra air outlet underneath that keeps the mom from weighing down the pup, and the pup can survive.