Why is My Saddle Slipping? Brain Fart Moment!)

I have a jump saddle that is slipping back on one of the horses I’m using it on. It’s a medium-narrow that is custom fit to my giant 17 hand OTTB. I use a square pad and a regular Mattes pad over that and a leather Stubben girth that I got in a bargain bin at Rolex a few years back. The whole shebang slips back- saddle, pads, and girth. The problem horse is a 16 hand OTTB with a pretty normal TB back (decent sized withers, but not crazy big) and he does have a somewhat forward girth groove.

I’ve been thinking that the saddle is too wide as that’s how it sits when you try it on static and that I’d need to use a front riser pad with it, but now I’m wondering if it actually needs a rear riser to keep from slipping back. I just can’t for the life of me remember what slipping back indicates fit-wise. I should know better, but I’m having a total brain fart moment and can’t figure out what I need to do to get a better fit with this saddle and help eliminate as much slipping as I can. I have a Mattes sheepskin pad with risers, but I was considering getting an Acavallo gel pad with either a front or rear riser for the added no-slip grip of the gel and need to decide which one will benefit me more.

The half pad will just be a short term solution- I know for a fact the saddle doesn’t fit the horse. But seeing as I don’t own the horse and am not sure how long I’ll have him, I’m not exactly jumping to buy him something custom. I will have a saddle fitter out later this summer to get a new jump saddle for myself and my other horse and do plan on having her look at this horse and saddle, but I have to decide on Bliss or Black Country first and I’ve only been mulling that over already for about 3 months, so it could be a while.

Saddles slip back for a few reasons, one being too narrow but without photos, it is hard to assess. If that is the case, padding will make matters worse for the horse. An uphill horse with a straighter topline behind the wither might need more depth in the rear so if the front does fit, a shim in the back would be fine. Many use breastplates to keep a decent fitting saddle in place.

Unless your horse never gains, loses fat or muscle, or does different work, he will change shape. Hence, the saddle fitting, sliding problem. I have a draft cross and oh, the woes.

He is not built particularly uphill- he is just barely level and prefers to drop his shoulder on the flat and over fences. But unlike the other horse, who the saddle is fit for and goes withers, dip, butt, this guy goes withers, flat, butt. I have been either not shimming or shimming up front because it fits a bit wide, so I will try shimming it behind with the Mattes pad and seeing how that works.

Would it also be worth noting that the problem horse has a forward girth groove? I’m currently using a normal girth on him, but would an anatomic girth actually help with this particular issue?

without seeing a pic its hard to tell. can you post a pic of the saddle on the horse’s back without any padding? then with padding and girthed?
ditto the too narrow comment. sliding back generally indicates too narrow, sliding forward indicates too wide.

Caved and had a saddle fitter who was not associated with the brand evaluate. WAY too wide- for both horses, including the one it was fit to. My sneaking layperson suspicion that fitters associated with the saddle brand, or it least the multiple ones I’ve worked with, are crap was confirmed. No general notes on why exactly it slips, but either way it looks like I’m in need of a new saddle.