You can use a dog box on your trailer to haul dogs for dog racing, hunting or any other reason. If you construct a dog box correctly, it can be used for a long time. Professional dog mushers carry their dogs in dog boxes all the time, and each type of dog box is different. However, there are some general steps that you can use to make a dog box for your trailer.
Cut six pieces of plywood that are 3 feet-by-3 feet. This is a standard size dog box for most middle breed dogs weighing between 13.6 and 31.8 Kilogram. Keep in mind that if you have a bigger dog, a dog that doesn't like confined spaces, or a smaller dog, you will need to adjust this measurement accordingly. Each person has their own preference for dog box sizes, and you might have to experiment with several boxes before you find one that is perfect, because each dog is different.
Lay one section of plywood on a work surface.
Screw four pieces of three foot long 2-by-4 boards around the base of the plywood, as if you are making a picture frame from it.
Use screws to attach 4 pieces of plywood to the base of plywood. If you set them up flush against your work surface, you will be able to screw into the 2-by-4 to attach them securely. This should form a box without a top.
Cut a 1 1/2 foot-by-1 1/2 foot door in the front of the panel you have left. You can hinge a plywood door with slats cut in it, install a pet door that can be closed from the outside, or create your own door out of metal or wood. The door can be any design, but it must have slits, holes or small boxes punched out of it so there can be air in the dog box.
Turn the plywood section with the door in it upside down and set it on the work surface.
Screw four pieces of 2-by-4 around the edges of the back of this piece, exactly the same as the base piece.
Set this section of plywood into the top of the box, and use screws to attach the plywood pieces of the sides to the 2-by-4s. You should now have a complete box, and one of the sides should have a door in it.
Paint the entire outside of the box with a waterproof outdoor paint. Do not paint the inside.
Attach the dog box to your trailer. You can do this several ways, but the best way is to screw through the bottom of the box in at least eight locations, to attach the box to your trailer. You can also attach it with bungie cords or metal strips that you have bent over the box.
Fill the box with straw before you put the dog in it. This will keep him warm in the winter and cool in the summer, and give him padding for the ride.