What do the dog sledding dogs eat?

Having raised Siberian Huskies, their are two answers here. First, like humans, it can depend on where they are raised. Regional human foods can be fed them (if you choose healthy ones for dogs - check with your vet) as well as standard dog foods. Second, if actually working the dogs, small portions multiple times per day of a high protein, moderate carbohydrate dry food is preferred for energy and stamina. The smaller portions keep the animal satisfied, but doesn't make it uncomfortable (remember last Thanksgiving?) so that it can concentrate on work. If the work involves long hauls without places to resupply, dry food is better due to weight considerations. Many sled dogs will eat raw or cooked fish caught on the trail, but like us humans, some will turn up their noses at foods they don't like; as with any dog you will have to find out the likes and dislikes of each particular dog.