His most noticeable fluctuation tends to be in the wither hollows- he has them as a matter of conformation, but he tends to have summers in light work because he doesn’t cope with heat very well. Combine that with good grass and he gets a little zaftig so the hollows fill in, whereas in the winter the saddle needs help being lifted up off of the wither. This is something that foam can do very well and has done very well for him in the past if it’s put in the right place rather than distributed over the entire bearing surface of the panel region- on a DVX, going +5 in the 4 region compared to the rest of the back tends to work well for him- but then it causes the saddle to sit high and create incorrect pressure over the trapezius muscles for the other 6 months out of the year. He was previously in a 4+5 3+0 and we’d talked about subtracting panel and shimming up, so he now has a 4-5 3-10 (a neutral panel wasn’t right for him over the summer.) This will be right on the money in June, but I need to experiment with the shimming arrangement in the front for January. I do have a set of shims I made for him out of running shoe insoles that supports that wither hollow area specifically, so I need to give that more of a try.
As a younger horse he had less fluctuation season to season, but now that he has the heat intolerance, the age-related changes, and the whole semi-retired thing, it’s part of the package with him. And for what it’s worth, his back is doing exactly what I hoped it was going to do this winter, so none of this is a surprise. The decision is whether to panel for summer and shim for winter; panel for winter and shim for summer; or go wool and have flocking adjustments done seasonally.