I've never seen this happen before. Is soreness a possibility? He cantered/bucked/trotted a LOT today (Loki really hyped him up -eyeroll-). Normally he just putters along at a walk, but he was really working it today. Cantering from one side of the pasture to the other (it's 5 acres), trotting after Loki, kicking at Loki with the back hooves because Loki kept nipping on his rump, bucking and jumping just because the weathers fine, the grass is green, and those are three geldings feeling darned full of themselves.
Heck, I don't even work him that much. 15 minuets at a walk, plus a minuet of trot in either direction on the lunge and that's it. I do that once a week, if. Just for the heck of it really.
I did observe him at a stand and at a walk. Both appeared normal. I didn't hear anymore clicking (hooves hitting together) maybe 15 minuets later when I called him over in the paddock. He was standing around in the standard position, at ease, slightly parked out in the back.
Ideas...? O-o He is shod, but everything's normal. No loose shoes or hooves in need of trimming.