I have had a few experiences with a horse a bit like you have described , a loan horse that came to us to be a companion for Charlie . She has sadly since left us and gone back t her owner
The first and the most important thing that they need to understand is that they can get you to go away when ever they want . I did this by watching for the signals of her disappearing into herself . It could be something small like a slight tense of the nostrils or even just a look in her eye . As soon as I saw this I would leg it
, I mean really leg it to at least
20 metres from her . She was very bemused by this and found it great fun . It looked like madness , me standing next to the horse then suddenly for no apparent reason running away from it like the hounds of Baskerville were after me . Very soon she figured this out to be a great game and we slowly changed her cue to me to something different , so it didn't have anything to do with her shutting down .
With her she would just shut down the moment a human appeared on the horizon . You have to work very slowly , never getting to the point so they do shut down . I never thought of trying anything ' practical ' we never had a training session either . I wanted her to understand that I would listen to her at every point and that I was her friend . So we left all normal stuff behind and just did extremely mad and crazy stuff .I let my imagination loose and thought of things that would interest , intrigue and excite them . Playing tennis in the field , do gymnastics , bringing some old metal drums and showing her how to make a noise . using lots of treats and rewarding anything she offers or tries . Also I worked with her only occasionally and spent most of my time working with my king Charlie around her . So she could observe Charlie's reactions to me and my love and connection with him . Give up on any goals that you have and let the horse choose them for you . It was only after a good many months of madness before she completely stopped shutting down and in all that time I kept all ropes and ties away from her . She learnt that she had the freedom to choose what she wanted . We sadly had to give her back to her owner , so she is now gone