I am posting for ideas, since I'm stumped.
On Saturday I noticed Raina took an off step every once in a while when Iseul and I went up to play around with her. It rose some alarm but I did a quick check and nothing seemed out of place or abnormal.
I went up again to see how she was doing and she was noticably off at the trot. She had some good steps in there but it was consistant enough to raise more alarm.
I hopped off of her and checked for any sole soreness. I tapped her soles with the butt end of the hoofpick rather firmly and there was no pain. I squeezed the bulbs of her hooves and she only seemed a little ouchy on the hind left, not the front left (or even the hind right if she was compensating).
Other than that, nothing. I checked her legs for heat, palpated her mucles, took a pulse on both fronts. Everything seemed normal and she didn't even flinch. The one hoof she seemed a tad sore on was the hind left when I squeezed the bulbs, but she wasn't favoring that one.
I'm having her checked by the farrier on Friday. She's due for a trim as it is so we'll kill two birds with one stone.
Any clue as to what might be going on? I'm thinking an abscess that's not sore enough yet to feel bad when I tapped with the hoofpick, but maybe it'll come up when the farrier pressure tests her.
She is barefoot and on pasture board. She doesn't have the typical lamanitis stance and is a good weight.
ETA: When I put her back out in the field she had no problem cantering back to the herd with her ears perked. She wasn't 3 legged lame or anything, just gimped at the trot enough to catch my attention and make me worry.