Well, mine is 7 and he still does as the OP's horse, only my guy DOES try to take flight!
I will be subscribing to this thread to keep up with the suggestions as well!
The above is great advice, and I've tried this with my gelding, but we would be there ALL. DAY. LONG. doing trot circles... And the last part about standing still giving them time to scheme...yes...my gelding's go-to move before doing something stupid or psycho is to stop and stand FROZEN...then all hell breaks loose...
My 13 year old TB horse still does it. They are prey animals. It makes them nervous that predictors can see them in the open, esp sensitive TBs. He has improved though so there is hope. It doesn't help that there are always deer and turkeys jumping out!
Horse is 3. As the others have said, just a baby. My best suggestion to you is to get him in his comfortable place and then bring him out of it a little bit. So you ride a bit in the woods where he is happy, take him a little bit in the field, do somethg to engage his brain, and then go back to happy place. Little bites.
He may need a leader. Get off and led him round the perimeter. Stop and look when he does. Relax. Let him eat. then get on and walk around. Give him a nice wee scratch on his neck just above the wither if he stops. It's a reassuring contact for a young horse, especially if he isn't used to being outside in big spaces.
I have a shedrow problem with my horse, but this same horse has had open field issues too. Yes, I did the big circles, in every place in the pasture, and lots of work in collection, etc. She likes to think there is something scary in the fence line bushes, honeysuckle, etc! Silly bird, or ?? to pop out and eat her. She has sharp ears, eyes, and a great sense of smell, she should know whatever "that noise was/is" is something which will not eat her.
I worked mine in the pasture today, and I did huge walking circles along the fence line out into the pasture, back and forth along the line. I had my spare horse "little old lady horse" grazing nearby-her choice. She was there to prove there was not something there to be scared about. She is 20 plus, she should know. ??
I will do this 7 days a week if I have to. This thread has given me the oooph to make her stop the insanity. She is fine on any trail with any depth of bushes, awesome with very technical footing/trails. But she is worried in her own pasture, or if I ride in a hay field and we come to the edge. Brat! It isn't like she was raised on a golf course, or foot ball field, or the sahara desert.
If she spooks, I turn her right away and do the same thing over and over, and move a little bit down some, then do the same thing over and over. Today she didn't spook, but was looking to. She was intense. So she got a good work out. She had sweat over her butt, which constitutes a good work out for a horse. BTW we only walked.
Wonder how many days this will go on? I am a former endurance rider, so I can ride a long time, many days in a row, any weather. It was hot today, humid too. We rode 40 minutes because she was finally being good. She got a nice cool soapy bath (first since last fall), and time under the fans in her stall. My horse is turning 7 this summer. It is time for this to stop! Ok, it is only a minor issue, but I am ready to see this "I am scared of the bushes along a fence line" to go away. Brat!
Will the insanity end? I will ride tomorrow and try to report back.