The vertical grills that are traditional to horse stalls is something we just won’t do.
Everyone at the track has stories of some horse hanging a foot there if it decided to play or kick.
Happens rarely, but why chance it, so that is not a choice.
The stalls we have now, we made them with horizontal bars for the fronts, but I am not sure that is a good idea between horses, just marginally better than vertical grills.
A horse can get a foot thru and back, but if one was to turn the head sideways and be very intent on getting to the other horse, he possibly could and then not be able to get it’s head back.
I think what we will do is open tops, don’t know yet if 1/2 left solid in the front, by the food, but the top some kind of material like the ones in that picture, 2" thick welded rod panels.
Each solid side now has three parts to it above the middle, will be easy to cut those out with a grinder and make some “windows” of that mesh material to fit there, welded or bolted in those spaces, three of them, or the two back ones only.
So much to consider, thank you for the ideas.