I have a spooky horse. I bought him off a trailer that had just rolled into Maine from Iowa. He is 26 now, but was just coming 7 when I bought him. BO (who was with me) had one of the barn rat teenagers get on him first in case he was nuts. He wasn’t. But it took me a while to figure him out. I had a lousy seat so I had problems sticking with him. It took a while, but I did not “train” him to cure the spookiness. He got better as the years went by, and I got better too. It is an unusual occurrence these days but now I get compliments on the save.
Noises are his problem, especially sudden loud noises or rustling leaves. I was working with a certified trainer (not Parelli). She hopped on him, told her mother to go into the wooded area and get ready to rustle the leaves when she got the word. Mom really rustled the leaves and trainer was on the ground instantly. We revised the process and started over with quieter leaves and mom closer to the tree line. He did okay, but that’s when I had an idea of what his problem is. Noises. He looks suspiciously at things that are not supposed to be where they are but he doesn’t spook - no noises. The combination of my becoming a better rider and his spookiness subsiding as he got older are what worked. It’s not completely gone. He still may react to a noise in wrong place or something really loud. Or rustling leaves. Nobody believes me when I tell them about the carnivorous chipmunk on the attack. It charged right at us rustling some leaves big time. We lived through it.
If a horse is a “looker” and keeps an eye on the universe looking for something deadly, he’s not paying attention to you. You are most likely doing the same thing - looking in anticipation, rather than paying enough attention to your riding. They are so fast when they spook that you won’t know what happened until after the entire process is complete. He jumps to the left. I created a mid-air correction to land on my left butt. There are enough little changes in your body that your horse gets the message: “We have to keep our eyes open, there could be an attack.” There still is a lot of disagreement about whether you should go to the problem so he can analyze it. If the plan was to walk by nonstop then work on that. I still have to know where the deer tend to be in the spring with fawns, and during hunting season in November.
My horse is pasture boarded with free choice hay. I’m not sure how you would analyze his food sources so you can pick out a combination that will calm him down. Spooking is hard-wired.