I’m not totally sure because he moved east and then the owner took him to New Bolton, and I got their findings second hand and know he was retired immediately following that exam. But on xray, his neck was riddled with arthritis, he had ECVM, and one of the lower vertebrae looked moth eaten, not just missing the lower part, for lack of the technical term. But his symptoms wound up looking like spinal cord compression, which at his age wouldn’t be wobblers but probably a complication from the arthritis. The bolting wasn’t the first tell, but he had mild, shifting, and unblockable hind limb lameness that would come on intermittently, usually showing up as trouble holding a lead behind or cross firing. After the bolting started, the lameness also moved to the front end. And there were days I couldn’t pick out a front foot without him trying to sit down. Some days he couldn’t back up at all. But then maybe you wait 20 minutes and try those things again, and he’d be fine. He did the electric butt scoot with me a number of times (the vets here advised we keep working him to make him fit for the move), and the one day he did it from the walk with me he was able to somewhat settle and finish the ride, but by that point, we had also been doing a lot of groundwork with him to try to bring him down when he’d get freaked out like that. He was generally willing to please. The bolting and the lameness symptoms did not seem to coincide, and he bolted less the more the neuro deficits became clear. One day he started limping in front after we had been doing w/t and poles for a while, shifting legs, and then was unable to back up, and he was calm as could be, even when he had some trouble walking on uneven footing back to the barn (I got off) until he snapped out of it and regained control of his legs.
Neuro disease progresses differently in each case. I’d exercised this horse for years with no problems. He went downhill pretty fast once symptoms started.