To be in the Iditarod, you need to have at least sixteen dogs that like to run. You need lots of stuff to be in the Iditarod: warm clothes, snow shoes, warm coat, etc.
The dog needs thick fur, but not so thick or the dogs get hot. If it's too thin they will be cold. Just make sure their fur is thick enough to keep them warm. Also the dogs need to be strong. They also need dog booties to keep their feet warm, but not too thin to make the dogs cold. Dog booties are like mittens to keep the snow out of their feet.
Mushers need tons of supplies to run the race. To keep them warm on the trail they need a sleeping bag that can keep the mushers warm at 80 degrees below zero. In their sled at all times each musher must have: about eight dog booties for each dog, snow shoes for the musher, 2 pounds of dog food and dog dishes for each dog, some food for the musher (like gorp), an ax, a first aid kit, a cooler to store food, a water bottle, a toothbrush, a compass, a parka, a cooker, a headlight and extra batteries, a hat, and a harness. A lot of mushers carry a gun in case a moose comes close to his or her team.