He is now in good physical health and weight. I've had him worked on by a good equine chiro, dentist, farrier, vet, etc. I've also addressed saddle fit to be sure that his tack has continued to fit as he gained weight and muscle. He lives out 24/7 on 5 acres with my son's pony and another gelding. Has access to a round bale of good hay and a nice run in. I also go out daily to feed him a meal of beet pulp, ration balancer, and fat supplement
So here's the issue. He really doesn't have any self-confidence. He loves to work, but introducing anything new is very nerve wracking for him and myself. Sometimes he takes new things in stride without any issues. But other times he has explosive responses of shying, spooking, bucking, bolting, kicking out, rearing, tooth grinding, etc. These responses are way worse outside the arena or off the farm. Trail riding is a disaster. It's almost like he mentally meltsdown and just check-out of his body.
To top things off, he's become super attached to my son's pony, but only when riding or working outside the pasture. When they are seperated while turned out (one taken in to work while the other is still turned out), there are no issues. But if they are both being worked and the pony goes somewhere else (trail riding for example), the meltdowns begin. When I take them somewhere off the farm (ie the local saddle club arena), my boy is a mess. He will spin and bolt to wherever the pony is in a panic.
When he's good, he's oh so good and so very talented. But when he's having one of his "moments", he's frighteningly upredictable to the point of being a dangerous. It's obvious to me that he doesn't trust me or view me in a leadership role. But he does enjoy being worked. I know that groundwork would be a great tool to help with this. I just don't know where to start. I've worked with many, many horses (foals, starting undersaddle, spoiled lesson horses, etc). I've always been the one people bring horses to when they're having training needs. Being in this position is just a bit overwhelming. The trainers I have access to (or that I know of) either don't work with this type of horse or their training style is way too rough for this guy.