I thought of this earlier when I remembered a case I’d had a couple of years ago. The horse in question was a pretty decent 2* horse. Over the course of the season his show-jumping became rather less fluent than normal and he’d roll the odd pole, which was most unlike him. He progressed to chipping in on the odd ocasion and started occasionally stopping, which he’d never done before. I’d given him a good check-over, but couldn’t find any obvious problems. The dentist was happy, the physio found some tight spots around his shoulders but he wasn’t really any better after her treatment. We were on the verge of sending him to one of the big equine hospitals for a diagnostic work-up when something changed. The owner took him to a jumping clinic to pop some little stuff and forgot to pack her 5-point breastplate. The horse started out sticky, as he had been for the past few weeks, but gained in fluidity over the course of the clinic and was nearly back to his old self by the end of the lesson – albeit over what were, for him, pretty tiny fences.
Then the penny dropped. At the beginning of the season they’d had a break-in at the yard and all their tack was stolen. When the insurance money came through they bought him a rather flashy new 5-point breastplate in a totally different style to the one he’d worn previously. This pretty much coincided with the start of his jumping problems. Obviously the horse felt restricted round his shoulders and unable to produce his trademark flamboyant jump. Once we suspected the breastplate might be the culprit the owner left it off and the horse’s jumping improved so much over the next couple of months that he was back to jumping clear round Intermediate SJ tracks. The breastplate went on ebay!
So my tip is that if things are going wrong strip everything back. Take off the breastplate and martingale, ditch the boots and fancy half pad and pop a snaffle and a cavesson on. Do you still have the problems? If not then try re-introducing your tack a bit at a time to see whether you can identify the problem. I’ve certainly heard of horses which can’t bear certain brands of boot which may touch the back of their knees when they tuck them up over a fence and other horses whose owners have bought them special scientifically-tested pads to level out the pressure under the saddle, but which couldn’t stand to be ridden in them.
You may well have a physical problem or a schooling problem; but it’s quick, easy and cheap to rule out your tack first!