After this he became really spooky and really unenjoyable to hack out. One day we were out hacking and he saw some riders in the distance trotting along the road. He literally flipped out, rearing, bucking, spinning, anything it felt to try and get me off. After a few minutes of this I eventually decided this was only going to end one way, with me on the floor and him bolting after the horses. I jumped off and led him back to the yard.
Since then he's been checked for all physical problems (spine, gastric ulcers, teeth, hind leg lameness) and nothing has been found. I've been working with a trainer who has been helping with groundwork and desensitising. Some of the exercises included a bit of lunging. Recently he has begun bolting on the lunge and i can't keep hold of him, he now seems to be in a habit of this, I can only describe it as a switch that goes off in his brain. He goes from being completely calm to the whites of his eyes showing, head up and looking absolutely terrified with no apparent reason. Only a flag is used for direction and speed, no lunging whips.
He has got so bad that I am now scared to lunge him, he has also started bolting when I lead him to the field. This is with a dually halter on which I did a lot of groundwork with him in the beginning.
Basically things seems to be going from bad to worse and I feel I'm running out of things to try. Join up in a round pen is a scary experience as he cuts in and bucks in at me.
Any suggestions would be greatly appreciated.
He's such a sensitive lovely horse but he has some deep rooted issues.