There are many different types of harnesses that one can get for carting. Each of the harnesses available are suited for different purposes. There are x-back and h-back harness types that are designed more for long distance sledding and weight pulling - these harnesses have a single point of connection with the load that is being pulled - be it a sled or a weight sleigh. There are other harnesses that have been developed for use with carts and these typically have 2 to 4 points of connection with the cart. I have three different types of carting harnesses which I will show and describe here.

The first I have came with my cart/sulky and is considered a parade harness. It is a simple affair and has a wide breast plate/strap that crosses completely from one side of the dog's chest to the other. It is a good harness for simple carting. It is easy to fit to the dog with several different points of adjustment. Because of this it can easily be used on many dogs. The thing that I do not care for in this harness is that it can be considered a restrictive movement type of harness because when the dog strides out in front the shoulders are somewhat confined by the breast plate.

There are two points of connection between the harness and the cart via a D-ring on each side of the harness at location near the dog's elbows.

Parade Harness photos:

The second harness I  have is a Siwash harness. The particular one that I have is a  Wilczek Siwash (nordkyn.com). This harness distributes the weight of the cart across the back and between the front legs of the dog. Because it does not have a breastplate like the Parade harness it is a non-restrictive type of harness, allowing the dog full range of motion in their front legs. This harness has four points of attachment to the cart - two points on either side of the dog's shoulders connected to the shafts of the cart, and two points at the flank of the dog to one or two points on the cart via traces (lines).

Siwash Harness photos:

The third harness that I have is the best of the two harnesses above and is a Pulka harness. It was designed for mushers who worked their dogs in the off season using carts that have shafts. There are two points or four points of attachment from the harness to the shafts - very similar to the parade harness. (howlingdogalaska.com)

Pulka Harness photos: