As a musher, you often need to move a lot of dogs from one spot to another. Simultaneously. With a reasonable degree of predictability. Frankly, if I let the dogs loose before hooking them up to the sled or the rig at least one of them will shoot off and run loose until the rest of us catch up. This seems to be the case no matter how large or small my team is. One crazy free spirit will always decide to march to a different drummer.
Above is my solution, a belt made with an old bicycle inner tube and a bunch of home-made lines. The red lines are for attaching dogs, the yellow lines are spare necklines. (In occasional instances of frustration, the dogs will start snacking on the necklines.)
One great thing about bicycle inner tubes is that they are free. Another one is that they provide a great deal of suspension. I also use bicycle inner tubes for skijoring and when I connect the dogs to a bicycle.
Buying a purpose-made skijoring belt costs the equivalent of literally hundreds of dollars. So easy to fool people who love what they do.