I am going to suggest that you have someone VERY experienced take a look at the other end of the horse. Specifically look in the mouth. My boy was VERY much like your boy. body sore all over, uneven striding, ex jumper, ulcery, would not lift back, did not want to go forward. We started with shoes, and hock injections. then he had his first dental and almost flew backward when the rasp hit 2 particular molars. bottom molars, first molar after bit gap on each side. Both abcessed, one fractured. The vibration of the rasp was more pain than he could handle even very sedated. REmoved those 2 teeth, he started to get better. Less body soreness, more willing to go forward. then after about 4 months he started to act funny again. Lost progress and went backward. Cue vet. Xrayed front incisors all 12 needed extracting due to EORTH. He was one of the few who don’t show much sign externally in the mouth but the xrays said it all. After that we REALLY began to make progress. Now a year and a half later we are going backwards again, but not as much. We have injected literally everything except SI. the most recent issue showed up right after the last hind injections. So vet did injected SI. And I stood there and said “please look in the mouth and redo the xrays”. Unfortunately he cannot tolerate the vets normal speculum owing to lack of teeth, it puts pressure on the canines. So we have a deal. Vet is going to buy different type of speculum sprecifically so he can do my horse, but in the meantime we are going to pursue SI comfort and maybe xray withers and back just to be safe. Hopefully within 3 months we will get to look in the mouth. It would not surprise me at all if that is where the problem is.
This was a long way to say everyone told me dental pain could not cause whole body pain. Baloney. When the dental pain was removed, my boy was a diff horse overnight. Some vets even think horses don’t feel pain from most dental issues. WTH? Good luck with your horse
