My gelding last year developed a couple pressure bumps near his spine. I did 5 laser treatments and they went away. Two months ago, they came back. Ugh. I ride in a Tammy Fischer treeless which we both like. I was riding him in a 3/4 in five star with no liner. My trainer had me switch a month ago to a 1 in five star with a liner. After riding, when I take the saddle off, the bumps are down 50%, but the next day they are flared up again. 

Under saddle, no issues whatsoever. Had him chiroed, etc. He moves beautifully. Has never offered to buck, rear, trip, anything of that sort. The bumps don't physically bother him to the touch, but I want them gone. 

Going to try an impact gel pad for a few weeks and see if that takes the bumps away. If not, I will look into a treed saddle.

I live in a very small town, where most of the ladies I know ride in a treeless. If the impact gel doesn't work, how do I start to determine what treed saddle I should look for? There are no saddle fitters around me within 500+ miles. No saddle makers either. 

I can't afford to buy multiple saddles and have to resell them on Facebook. He is more narrow. I will attach pictures of him, so if someone could point me in maybe the right direction that would be great!

Talked with my vet this morning, and maybe he would do better with a treed saddle. I switched him to a treeless 2 years ago because the treed saddle I had caused his back to become sore. 

How old is he? He's pretty atrophied through his shoulders and along his topline which I've found to be fairly common among treeless saddles. I wouldn't be surprised if that's what's causing those bumps. 

My only suggestion would be try everybody's saddles that you can get your hands on. Learn a bit about saddle fit so you know what to look for. Unfortunately the only way you're going to find a saddle that you have to buy once is if you get a cast done of his back and go custom. And that's if his back doesn't change and fill out more. The buying and selling game sucks but if there's no one in your area, that's really your only option. I've bought and sold probably 3 dozen saddles fitting my two horses. Just the name of the game

He just turned 7

I would have guessed older judging by the divids behind his shoulders. Any idea what's causing the white hairs on his withers? Treeless saddles work for some horses but they're not saddles you can just throw on any horse - just like ANY saddle, it's gotta fit. 

My trainer said the white hairs are from the saddle. My performance vet has never pointed out his shoulders to me. I just don't even know what brands to start looking at first..

I would start with your friend's saddles. Also when you go to a barrel race ask to try different saddles. Most are happy to help.

My horse is hip high and also has muscle atrophy on her back. With the help of Kari at PSC saddles, I purchased a used PSC and a pad she recommended. Its only been hardly a month but so far so good.