You can sort of see proper saddle placement here (the front saddle bag doesn't cover very much):
The girth is in the correct place... it needs to be well away from his elbows... but the rigging (where the girth attaches to the saddle) is just too far forward- should be more under the fender than in front of it.
My guy (pictured) is also high-withered, though very short-backed. On your horse the saddle should *under no circumstance* come that far back on his spine- for one his back is long enough and for two my guess is you'll be using a treed saddle. Saddle pictured is a Bob Marshall Treeless- there is no rigid tree to push on his spine and create pressure. He does very well in it and is quite comfortable; they are relatively inexpensive for a western saddle although rather more than a Wintec (anything of decent quality will be, I'm afraid to tell you, unless you pick up a major steal or a very used saddle). They pop up on eBay from time to time although you have to know what you want because they tend to go pretty fast.
For your horse, I would start with a Skito Equalizer foam pad: he has enough back atrophy that he needs the help. From there, fit a saddle. If you go treeless, a Skito is basically required; if you don't, it's not a bad idea at all. They don't come cheap but are worth the expense, and last quite a long time with proper care. They are also great for using under bareback pads.
I would also keep hunting on the stomach issue, because while fixing the saddle will help tremendously, the fact that he's 7 or 8 and a hard keeper, along with the issues he has, really makes me think that he may have some irritation. The sweet feed, if nothing else, can do that. Pulling him off of the sweet feed and adding in free-choice, good quality pasture or grass hay with a feeding of alfalfa each day could tell you whether he has any stomach issues just by itself... diet is a big factor.
The girth is in the correct place... it needs to be well away from his elbows... but the rigging (where the girth attaches to the saddle) is just too far forward- should be more under the fender than in front of it.
My guy (pictured) is also high-withered, though very short-backed. On your horse the saddle should *under no circumstance* come that far back on his spine- for one his back is long enough and for two my guess is you'll be using a treed saddle. Saddle pictured is a Bob Marshall Treeless- there is no rigid tree to push on his spine and create pressure. He does very well in it and is quite comfortable; they are relatively inexpensive for a western saddle although rather more than a Wintec (anything of decent quality will be, I'm afraid to tell you, unless you pick up a major steal or a very used saddle). They pop up on eBay from time to time although you have to know what you want because they tend to go pretty fast.
For your horse, I would start with a Skito Equalizer foam pad: he has enough back atrophy that he needs the help. From there, fit a saddle. If you go treeless, a Skito is basically required; if you don't, it's not a bad idea at all. They don't come cheap but are worth the expense, and last quite a long time with proper care. They are also great for using under bareback pads.
I would also keep hunting on the stomach issue, because while fixing the saddle will help tremendously, the fact that he's 7 or 8 and a hard keeper, along with the issues he has, really makes me think that he may have some irritation. The sweet feed, if nothing else, can do that. Pulling him off of the sweet feed and adding in free-choice, good quality pasture or grass hay with a feeding of alfalfa each day could tell you whether he has any stomach issues just by itself... diet is a big factor.