Aim for Correctly Fitting the Harness and Help to Maintain the Horse's Health
There are a few points to consider for correctly fitting the harness onto the horse:
If you consider to buy a new harness and a collar or breastcollar, you should ideally take the horse with you to try if the harness is fitting correctly. Many horse tack suppliers give advice on how and where to take measurements for the correct fitting of the different harness parts.
A collar is a bit like a saddle, it is best individually fitted onto the horse.
Buying a used harness requires also full concentration as it is essential to detect any faulty pieces. A good tip is, never to buy when light conditions are not good. You will not have a chance to detect faulty parts!
In both cases it is best to have somebody experienced beside you, it almost certainly saves you a lot of trouble and money.
..and it really should not look like this one:
So, what has to be considered to ensure to get a comfortably fitted harness for the horse?
If fitting the harness, the collar should lie flat against the sides of the horse's neck and must not pinch the skin.
Between the windpipe and the bottom of the collar should be enough room to pass a hand freely in between when the horse stands in a normal position.
A straight collar is less likely to rub and straight hames are easy to get.
A bent collar (Kay-collar) follows the shape of the shoulder and lies back towards the wither.
One of the most frequent causes is friction which builds up between the skin and the collar's surface, as there is constantly movement and pressure when the horse is in draft. It is essential therefor that the collar's point of draft lies on that part of the shoulder which moves least.
If a collar is too low, it lies over the shoulder-joint and will always move over that area. During draft strong friction forces occur and the top of the collar will tip forward.
A too wide collar will slip from one side to the other, because it is lying loose on the shoulders. As a result of this movement a gall will develop soon just under the point of draft.
A collar that is too long slips upwards and backwards, if the horse is pulling.
The open collar can cause injuries if the housing strap stretches and the collar opens and closes with each movement. The skin on top of the neck will be pinched and injured.
An ill-fitting breastcollar will cause skin injuries and skin soreness in the area of the shoulderjoints if it sits too low.
The use of trace fixations which are allowing them to follow the movements can avoid such injuries. (e.g. sprung trace hooks or swingle trees)
It is also not good for pulling heavy loads as the draft load is not spread evenly over the whole chest and shoulder area.
If you are not sure or just starting off with driving learn all about fitting the harness under supervision of an experienced driver.