So, since at least about last Monday/Tuesday my pony has been stiff at the walk on his right hind, and it looks like his stifle. He only looks stiff tracking right, but not tracking left. He's also perfectly fine at the trot, doesn't look even the tiniest bit lame or stiff. I walk-trotted him lightly for 5 minutes and his RH from his stifle to fetlock was hot. Any thoughts on what could be wrong with his leg? I've had him for 8 months and no lameness problems. It's also been 7 weeks since he's gotten his feet done, and I'm having the farrier come out and trim his feet on Thursday (he goes barefoot). He's 13 and it's been getting cold, but the past few days have been in the 50's, not down in the 30's like it was for a few weeks.