A half dozen dogs, snow, and a sled aren't necessary to participate in the sport of dog mushing. Dog scootering, a type of urban dog mushing, is great fun for both dog and man and a wonderful way to get larger dogs the exercise they need. Only one dog is necessary if riding on the flats, but two or three enthusiastic pullers can make for a wicked good time :).
The dogs in this video are Belgian Tervurens, aged 3 and 9. Any dog over about 30-40 lbs can pull an adult on a scooter on flat ground if they're eager for a run, although some breeds (huskies, malamutes, samoyeds, etc) are particularly well suited. It does take some dedication to teach directional (left-right) commands, but this process can be sped up greatly if training with another experienced team or leader.
Urban mushers use every manner of wheeled conveyance from bikes and 3 or 4 wheeled carts to rollerblades and skateboards, but one of the easiest and safest vehicles is a 2 wheeled scooter. Usually equipped with BMX bike tires, front and rear brakes, a non-slip skateboard deck, and even suspension systems, scooters provide plenty of control and stopping ability, good ground clearance, light weight, low rolling resistance, and are easy to bail off if (when) your canine companions abruptly decide the squirrel on the side of the trail looks like a tasty snack.