I think the OP said she intended to give him some time off, not keep riding him. If it's arthritis, though, that can be a hard call. Time off/stall rest sometimes will make it worse, but the horse is in pain when you ride, so what can you do? I think a vet confirmation that it is arthritis is first priority, then some kind of treatment (legends+bute is what we just did for my mare), and light exercise with a pain killer. Maybe hand walk? Maybe just ride him in good footing at a walk? If it's really arthritis, he needs to move.
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