When I ride my horse on any kind of trail ride he starts to freak out. He rears, tries to run, side passes, crashes into the forest, fights me the whole way and and is very alert when we get to the opening of a trail. I don't know what to do about it. Any suggestions?
( my horse is 29 but in great shape, and very broke. He was also taken on trails by a past owner who would ride him drunk and the horse would come home without him sometimes, but that was over 20 years ago)