Most people that have a sled dog breed have at one time or another considered trying him or her out pulling in some form or another. There are really a very wide range of types of winter sledding or dry land pulling, carting or racing that dogs can compete in year round. Knowing which type of sport you want to do will make a bit of a different in how you train the dog.
In general all types of dog related mushing, the correct term for driving dogs, will include the dog becoming comfortable with several new and very different types of commands, equipment and activities. Not all sled dog breeds are naturals at this, and lots of other breeds are excellent at harness work, especially as a single dog in a harness.
Most true competitive sled dogs are bred for the sport and are trained as such as puppies. These dogs tend to be both purebreds and mixed breeds and typically include the northern and spitz types and breeds. However, great mushing or sledding dogs in the past have also included purebred and mixed breed Standard Poodles, German Shorthaired Pointers, Akitas, Chow Chows, Foxhounds, Staghounds, German Shepherds and even the heavier breeds such as Newfoundlands and St. Bernards crossed with a northern type husky.
For non-competitive or non-sledding types of events such as skijoring, which is being pulled on skis by a dog, scootering, being pulled on a non-motorized scooter or bikejoring, being pulled on a bike by a team of dogs are popular activities. There is also a unique sport in Europe called canicross where a cross country runner is actually assisted and pulled by a dog in harness. These events typically use one or two dogs in harness which makes it much easier to get into the sport than the competitive dog sled racing that requires teams of highly trained and conditioned dogs.
Any medium to larger sized dog can be used in these types of activities. Generally for scootering, skijoring or bikejoring the dog needs to be at least 30 to 40 pounds in order to be effective at being able to pull an adult with proper conditioning and training. There is no maximum size but larger dogs are not necessarily better or faster than the medium sized dogs at these types of events. Any purebred or mixed breed may be a good match provided they are willing to work for you and love to run, jog or walk.
The equipment is really minimal as well. A good quality specialty dog harness, ideally made of light weight nylon is the best option. This harness has to fit your dog snuggly but not too tight and should not pinch or bunch the dog's skin. A harness and a gangline, which hooks from your wagon, scooter or sled and the dog are readily available in most dog stores or online for less than one hundred dollars. In addition you should also have specialized dog boots, particularly when the dog is just getting started. These boots can be leather or nylon and protect the feet from wear and tear on cement, dirt, hard ground or on the snow. Finally you also need a good platform to stand on, a scooter, wagon or sled, which has appropriate tires or runners as well as brakes. Brakes are essential to prevent the device from running into the dog when he or she stops. If this happens it can often ruin a dog from pulling not to mention cause serious injury and even broken bones.
To start training the dog the first step is to get him or her comfortable in the harness. Put it on, without the gangline, and encourage the dog to move about. Gradually leave the harness on longer and take the dog out for a walk with the harness on. If it fits properly and is not causing any discomfort, the dog should adjust within a few days to the feel of the device.
The next step is to teach the dog to respond to verbal commands when you behind them. This will be a huge adjustment for a dog that has been taught to heel as he or she will wait for your move to actually get going. A good idea is to work with a dog that is already trained in a double harness single file in front of your dog. This way the other dog is really training your dog to listen and respond to commands.
If you can't use another dog, try another person with a very loose lead to your dog. This individual should not interact with the dog verbally or physically or provide rewards, rather they are there to cue the dog through the lead as to what you are asking. You can also have two long leashes, one on either side of the breastplate of the harness or the dog's collar, in which you can signal turns as you would with a horse's harness, although no bit and bridle!
The first command is the "go" signal. You can use any word you like including mush, hike or start, but don't use "go" as that sounds too much like "no". Once the dog starts moving the gangline between you and the dog will tighten, causing most dogs to stop as this is what he or she has been trained in leash work. Repeat the command and signal the handler to cue the dog to move forward. This can include walking briskly ahead of the dog but not with the dog in the heel position. Give praise when the dog is moving. When you say "whoa" or "stop" pull back gently on the two leashes, but not on the gangline as this is constantly going to have pressure from your weight.
Teaching the dog not to come back to you when you stop is also a change for most dogs. You can use the sit and stay command or you may also want to use another command such as "rest" or "out", indicating the dog is not to return to you. Right and left or gee and haw can be taught using the leashes on either side of the collar.
Once you have go, stop, right and left under control, the next step is to hook up the sled, wagon or cart. Go slowly and ensure that the dog is comfortable before running or taking the dog out on any trails or public areas.