Saddle fitting is not an easy task or a perfect science. There is no such thing as one saddle fits all horses. An uncomfortable saddle can create unsoundness: saddle sores, muscle and skin problems, friction rubs, dry spots and galls.
Saddles will change their fit as your horse matures. He may fill out or thin out, depending on the level of care he receives. It is easier to fit a horse that is in shape, than to try to fit a thin horse whose shoulders are prominent from lack of ‘groceries’. If your new horse is not in the best of shape, you may want to get his weight up before purchasing anything.
When determining the size of a saddle, one thing you need to take into consideration is the length of the horses back. Some breeds, such as Arabians, have shorter backs and will need a saddle with either shorter skirts or rounded skirts. The skirt should never hit the point of hip/loin when adjusted properly.
When fitting a horse, stand him/her on level ground. His withers and croup should be the same level or special fitting may be required. Place the saddle just after the shoulder. This is the boney protrusion at the top of his shoulder blade, at his withers. A saddle should never rest on this bone. I like to ‘load’ the saddle up a few inches higher on the horse and gently slide and rock it into place comfortably behind the shoulder blade (scapula). I do not use a blanket for my first fitting test. Never drag a saddle forward into place, as it bends the hair forward causing discomfort and sores. Saddles tend to find their place if you try not to force them into a spot they do not fit. Let your saddle find the final resting spot, and if it’s too far back, the saddle simply does not work for your horse.
The saddle should clear the withers by 2 inches, give or take. It should allow free movement of the shoulders, be the proper length for the back, and when viewed from the side, the saddle should appear to sit balanced; not high in the front or the back. If you are missing any of these points, stop and return the saddle. You cannot adjust these with a pad; it is best to find this basic fit first.
If the basic fit looks good, slide your hand under the saddle at the front, and feel for pinching. All the points should rest with equal weight distribution at the front. There should be no spaces where the saddle does not meet the horse.
Now slide your hand in the middle, under the saddle at the side (just behind the fender). If you feel a space there, it is called ‘bridging’ and will put too much pressure on the front and back of the saddle. This area should sit flat against the horse.
The saddle should sit squarely on the back. When viewed from behind, it should not tilt to one side. When you look through the back to the front, there a channel that clears the back. Saddles should not rest on the spine.
Now add a saddle pad (see below for descriptions) and sit in the saddle. You should feel centered, not tipping forward or backward. You should be able to get 2-3 fingers under the gullet for wither clearance. Your legs should hang down straight, not in front or too far back. Do they feel comfortable or unnatural?
You should feel well balanced in weight distribution. The center of the saddle must be level; it is where you will sit, and it will affect your aids and balance if you do not feel comfortable (or able to ride properly). It is better to have a saddle that is a bit bigger than one that is smaller.
Slide your hand under the front and test for pinching while you are mounted. You should feel even weight distribution, with no spaces. Feel that the back of the saddle is not rising, and matches the shape of the horse’s body. The spine should be clear from front to back.
Test to see if the saddle rocks on the horse’s back. You need to be gentle while doing this, but do it with enough pressure to find your results. Saddles should not move very much from side-to-side. You should never have to constantly readjust your saddle after every maneuver.
Test for the saddle tipping up too far (front to back). Grab the cantle and pull up gently. Some poorly fitting saddles will tip right up vertical on a horse at a hard stop. My saddles have no more than 1 inch of lift when pulled gently, and about 2 inches when really tugged on.
Ride the horse and test the sweat marks. There should be a solid sweat pattern, not spots of sweat here and there. Solid sweat marks show even weight distribution. If you have a wool pad, you may want to use a piece of sheet or thinner cloth between the horse and pad to find the sweat marks. On extreme pressure points, the dirt from your horse will grind into the cloth.