A harness is basically worn in connection with a collar and used in place of leash attachment. While a collar only surrounds the neck, harnesses have a loop that encircles the torso as well, with connecting straps between them for reinforcement. This vogue allows for division of force which may prevent choking and a less chance of slipping out than may be possible with only one collar. Harness usage is growing in popularity among many pet owners- generally for those with small breed dogs.
Recently, pet clothing frequently sports a properly-placed button hole for hooking a leash to the harness worn under the garment. Dog harnesses designed to look like attires and lessen the stress on a small dog’s neck while walking on a lead. Racing harnesses have less weight, and are shorter than other harnesses. The X-back harness, so called because the straps form an 'X' across the back of the dog, is used more often than the H back, with short parts that ride far forward on the dog's body recently gaining in fame. The Y back or hybrid harness is ditto in vision to the H-back.
The tug line attaches to the harness on top of the dog's back and stretches parallel to the ground or upwards to the skier, bicycle, or other load. These harnesses are available online.