To teach your dog to pull a weight you will need a harness. If you don't have one available you can fashion one out of a rope making sure to tie it around the dogs chest, which is very strong, and around his stomach. Make sure that the ropes pulling area is on top of him so your dog can harness all of his strength to pull forward. Start off with a weight light enough so it won't hurt your dog. Don't make him pull on the weight immediately, have him tug on the weight to get the sensation and then have him slowly move forward while pulling on the weight.