Now, for obvious reasons, if you use a treeless saddle, your saddle will fit almost any horse, as long as the horse is not extremely narrow or long in the back. But, be aware that these saddles can be quite expensive, and the special blanket that has to be used with them are as well. The only discipline in which a treeless saddle is not available for, to my knowledge, would be roping, either calf or team, and bull dogging or steer wrestling. The tree is needed in those activities for extra support to the horse's back. The main fitting issue with a treeless saddle is it properly fitting the rider, but I'm not to that part of this subject yet.
Regardless of whether you ride English, Western, Australian, endurance or what ever type of saddle, there are different tree styles, gullet widths. There are even saddles in which the gullet width can be changes, but those are mostly English style saddles in my experience. If you are not sure if your saddle fits your horse properly, you have a few options. The cheapest option is looking at how it sits on your horse's back without the pad or blanket, and without being cinched up at all, simply placed on their back where it goes. It should appear level, with neither the front for back being higher or lower than the other. You should be able to run your hand between the saddle and the horse's back from front to back on both sides, with little resistance and no gaps or pressure points. One of the easiest ways to tell is when you take the saddle and blanket off after a good ride, in which the horse begin to sweat. If there are any dry spots, that is where the saddle is putting more pressure and it doesn't fit properly.
Another cheap way, considering your internet speed and usage, is to look up videos on the internet about fitting saddles. I'm positive that youtube will have multiple videos on the subject. Most reputable tack stores will have someone that knows how to properly fit a saddle to both the horse and the rider, and most will not mind your horse being hauled to their place. Some places may even check your current saddle for proper fit, in hopes of you remembering that in the future when you want a new high ticket item. If you have the resources, you can also hire a professional saddle fitter to come to your place and evaluate your horse for saddle fit.
** Something to keep in mind. Saddles fit differently, as the horse's body condition changes. Think of the saddle much like your favorite clothes in this manner. As you gain or lose weight, the clothes fit differently than they did. The same goes with a saddle that fits a horse. If th horse was in tip top condition when you had the saddle fitted to it, it may very well become ill fitted as the horse loses conditioning for whatever reason. So, just because the saddle fits today, does not mean that it will still fit properly six months from now. So, with that in mind, saddle fit should be checked regularly. And anytime there is what seems to be a sudden change in behavior that is not favorable, like grumpiness, bucking, rearing. Check the saddle for proper fit, and other areas for pain before assuming that it is training related. It may take a chiropractor and some time for the horse to realize that the saddle is no longer the problem, but maybe it was to begin with.
Back to the subject at hand. A saddle that is too narrow places all of the rider's weight on the outside edges of the tree, instead of spreading it evenly over the entire tree like it is meant to. Think of it like your 10 pound puppy standing on you where most of it's weight is on one of it's legs. It doesn't take long for that puppy to feel a lot heavier than it actually is. Whereas, if that same puppy is standing squarely on all four legs, you barely notice it at all.
The too narrow saddle also pinches at the shoulders and/or the hips, causing a restricted movement. You will probably notice a change in the way the horse moves. Think of this like wearing a button up shirt that is too tight across the shoulders and chest. If you stay within the confines of the shirt, it greatly reduces your range of motion. The same goes with pants that are too tight, especially if those pants are made of a material like denim that does not easily stretch. Don't believe me, put on the tightest pair of jeans that you can fit into, and try to mount a tall horse from the ground. Then try it again with a pair that fits properly. It will be a whole lot easier the second time, I promise.
Over time, using a saddle that is too narrow will produce a sore back, white scars from pressure sores, an altered way of moving, and will usually change a horse's attitude about being ridden, but not in a good way. Most of these issues are correctable, with usually some adjusting by a chiropractor, a proper fitted saddle, time, and exercise. The only one that can not be corrected or fixed is the scars from high pressure areas, which these usually show up around the withers.
A saddle that is too wide, will rest the majority of the rider's weight directly on the horse's withers and/or back bone, instead of spreading it over the total area of the tree like it should. These saddles are easier to compensate for with pads that are built up on the sides, but a properly fitted saddle is still better than just making due with pads. To give you something to compare this to, imagine being on your hands and knees on the floor, and someone else placing 10%, 20%, 30%, or even 40% of your body weight directly on your spine. Doesn't sound comfortable to try, much less to try to move around with it for very long on your level floor, much less outside on uneven ground for 30 minutes or longer.
Needless to say, this type of ill-fitting saddle will definately have you calling the chiropractor, if left unattended to. Of the two main types of fitting issues, this one is easier to correct with saddle pads, especially if you buy a pad that has adjustable shims, shim pockets. These pads are usually plain colored and ugly as home made soap, but can be covered with a navajo blanket of your choosing. I would rather have a saddle that is too wide than too narrow, because it can be adjusted somewhat with a pad.
Now, in a perfect world, all horses would fit in one width of tree, and I mean fit it properly. In a near perfect world, all horses would fit into one of the categories above, wide or narrow. Alas, this world is no where near perfect, and many horses fall somewhere between wide and narrow, and some are a combination of the two. Ever seen a horse that the saddle fits toward the back, but is too wide at the withers, so it sets almost directly on top of the withers. You try a narrower saddle on the same horse and now it fits better at the front, but is too narrow in the pack and pinches the hips. What do you do for this horse?
There are a few issues for this horse, and the first couple are restricted by your budget. The first option is to have a saddle custom built, tree and all, to fit the horse and you. This option is VERY expensive and out of reach financially for most recreational riders and some that are considered professionals. Another option is going treeless. This can also be expensive as the cheapest quality treeless saddle that I have found was >$800.00, and they can go up considerably from there. The final option is to choose the wider treed saddle, and use a shim pad to fill in the gaps at the shoulders, while making sure that the spine/withers have good clearance of the saddle with weight in the saddle and the girth tightened properly.
A saddle that is ill-fitted to the horse also effects you! A saddle that is too narrow will leave you sitting way above the horse, and leave you with an unbalanced and disconnected feeling. A tree that is too wide will have you closer to the horse, but will leave you feeling unbalanced from side-to-side as the horse moves beneath you. A saddle that is too wide in front but fits in the back, or a saddle that fits in the front and is too narrow in the back, will leave you feeling tipped forward and unbalanced. When the saddle fits the horse properly, it will actually help you stay balanced instead of throwing you off balance. Now that is not the only balance issues that you may or may not have, but your saddle should not hinder your balance in anyway.
Now, on to the saddle fitting you. To me, I prefer the saddle to fit like a good pair of gloves or jeans. It should neither be too tight not too loose. I'll explain the seat fitting first.
A saddle that is too small will push your center of gravity up and out of the saddle. Just a small amount of unexpected movement will place you firmly on the ground, unless you are extremely talented at hanging on and part tree frog.
A saddle that is too big, will not help you hold your seat because it will offer you no support, which is kinda on of the purposes of the saddle to begin with. A rider should not have a whole lot of movement from front to back in the saddle. You should lean forward from the hips, not actually slide forward in the saddle. You should sit deeper with your seat, and some lean slightly back from the hips, not move back in the saddle completely.
A saddle that fits you will feel snug, not tight, but allow for some movement, but not excess movement. Sounds confusing right? Ladies can relate proper saddle fit with a good pair of control top pantyhose. Too small, and they cut you in half; too big and they don't do their job. When you get the right fit, it helps you control what needs to be controlled, but doesn't really restrict your range of motion. Guys, I guess you could compare it to a jock strap. Sorry for being so personal with these comparisons, but they were the best ones that I could think of.
Once you make sure that the seat fits you properly, you will need to adjust the stirrup length to the proper fit for you. Stirrup length is something that varies greatly from rider to rider, and to most riders it is influenced greatly by discipline, experience, and personal preference. At first riders may want a little more contact with the stirrup, and that is fine; as their confidence grows so can the length of the stirrup leather.
Too short stirrups. If you stand up in the stirrups and can place more that 4 of your fingers between you and the saddle, your stirrups are too short. If you look like you are sitting in a chair, they are too short.
Too long stirrups. If you have to keep your legs completely straight to keep any contact with the stirrup, they are too long. If you are having trouble swinging your off side leg over, try shortening your leather a notch or two and try again.
Right length, you will know that your stirrup length is right for you, when you can sit, relaxed in the saddle and maintain a comfortable (for you) level of contact with the stirrups without having to push down or pull up your feet. For me, I know that my length is right when I can feel light pressure from them on the balls of my feet, with my legs totally relaxed as the horse walks around. I keep my heels down to where it looks like I am standing on a level surface barefoot. After several minutes of riding, I should not be feeling it in my knees. If I am, they are too short. If I am constantly loosing a stirrup, it is too long.
Now, regardless of discipline, every rider should learn to ride every gait and several maneuvers without the aide of stirrups. This is extremely difficult for some riders, especially if they have balance issues, but it will show you what you need to be working on, because 9 times out of 10, a rider's weaknesses become very obvious when a stirrup or two are lost. Now, there are the rare riders that naturally, actually ride better without stirrups. These riders actually need more work with the stirrups.
Ok, now that saddle seat and stirrup length have been looked at, let's look at one final point, that to me is usually determined by discipline and rider preference; and that is stirrup width, which seems to be a mostly Western discipline issue, but still bares looking into. If you spend long hours in the saddle, either trail riding, ranch work, or training multiple horses per day, a wider stirrup (1 1/2" - 2" wide) gives you more support. A lot of ropers prefer a wider stirrup. To me, they are too heavy feeling on me and I don't like them, so I don't use them. Then there is the narrower stirrups (1" - 1 1/4" wide), they do not offer as much support or gripping surface. These stirrups are lighter feeling, but easier to lose, so if your riding ability falls apart with the loss of a stirrup, either work to improve it or stick to a wider stirrup. Then there is the oxbow stirrup (< or = to 1" wide), and these are an acquired taste, ability, or whatever else you want to call it. I am still getting used to mine, and if I could find lace-up boots that weren't work boots, I would go back to the stirrups that came on my saddle so quick your head would be left spinning like a top.
Once you get the seat fit, stirrup length, and if applicable stirrup width right for you, you can enjoy a comfortable and secure ride that is not interfered with by a piece of equipment that is made to help you. A properly fitted saddle is equally important to both horse and rider, and is something that should be checked often, on both sides of it, because as you and the horse change shape, the fit of the saddle changes as well. This is something to always keep in mind.
Good luck, happy trails, stay safe, and God bless you and yours.
Until next time,