I have a 13 going on 14 yr old OTTB, left track sound and went into career as hunter/jumper and low level dressage training was in progress. Purchased as a 9 yr old, to become a pleasure horse that I could learn on and take clinics, didn't head in any particular direction with him - just wanted to find something he enjoyed. He can be a bit spooky, but a lot of time and money was spent trying to figure out if it was pain related, coming up with nothing. In the last year or so I started to notice a re-occurring "obscurity". When travelling on a left-hand circle, head and neck counterbalanced to the outside, he has a rough gimp and bobs his head. This is NOT present at a walk, canter, in any other direction, or even in the same direction with straight or inside bend. ONLY if he's looking to the outside, at a trot on a left hand circle, ridden, or on the loose. Hind end lameness has been suggested, but aside from in that particular position, there is nothing visible to the eye, or when trying to locate the pain by hand/physical inspection. I indicate that it's pain related as I buted him and tried to replicate the concern...no head bob, smooth sailing. Has anyone seen or heard of something similar that might help point me in the right direction?