I've thought about there being something painful on that side, i've recently gotten him a message, saddle fitting, the vet has been out, and i've looked into previous injuries on that side. He did have a stiffle injury 4 years ago, but he shows no discomfort in that area. As far as the message & saddle fitting, they found most of the " problems " with tense muscles & pressure points on the left side. I've also found no cuts, scratches, ect.
Does anyone have any ideas as to what could be causing him stress? Has anyone experienced this before?