My new horse has a very flat back and is young (4) and can be a bit spooky
If this is true (it’s always relative
) then most of the suggested saddles are duds - way too curvy in the tree (though sometimes a manufacturer known for a curvy tree will have a flat tree option that gets out into some saddles) … also consider whether the flat is width & length or just mostly one rather than the other …
If horse is a typical 4 yr old, it’s unlikely that the saddle that fits at 4 is going to fit at 5 (or even at now + 6 months) so take that into consideration … do NOT buy a dressage saddle & a jump saddle now, instead invest in single saddles that you feel comfortable flatting & jumping in.
(Based upon my experience with the straightest back horse (every fitter has ever seen) with wide shoulders & not a lot of back real estate: County Stabilizer - regardless of any personal failings (flap not forward enough, no blocks, minimal blocks, ugly color etc) this saddle may have, it has a flat open seat so allows greater range of rider position, has that flat tree with shorter tree points for the horse, wool panels so fit can be adjusted within reason, some will adjust the tree (though County does not support this))
For your security, you can modify/add blocks (go Velcro): if you find a Conquest, it has the deeper seat and big blocks (standard) but it won’t cross over near as well for dressage work (it’s perfectly fine for training level) - these are on the same tree as the Stabilizer.
Equipe also puts out a saddle that fit this (my) horse, had saddle adjusted to horse … after several rides, horse was done - even though everyone agreed that fit looked fine (horse was also no longer 4 though :lol: )
Black Country should also have some trees that suit, so I’d book demos with both & see where it leads.
There may be other saddles available depending on your area - if you speak with reps/fitters, they should be up front with tree types & how likely you are to find what you need in a used saddle.
I should also note that the crazy sensitive horse in my anecdote did NOT agree that a deep seated Conquest was similar to a flat seated Stabilizer (we ordered a Stabilizer seat with Conquest panels - got a medium forward flap this way, chose smaller blocks, panels were custom)