hey guys...this is my first time on a horse forum, but i really need help. i have a ~15 yr old gelding thoroughbred (teeth are bad and no papers, vet said 14-16). last year about 2 weeks after we showed 2'6" at a local show in august my horse was suddenly lame, and about a week later (early september) had a fever of 102 for about 2 weeks. he got better with antibiotics, but noone ever figured out what was wrong. from then until spring my previously bomb-proof horse spooked at anything and everything; he only got sane with outside turnout (tried smartcalm and other products). He was awesome this summer and we just started to jump again. however, last sunday (10 days ago) we had a barn picnic and he seemed semi lethargic. the next day he had a temp, was pawing, and had to be switched to wet hay and bran mash and he was on antibiotics and banamine twice a day for about a week; i was happy to hear yesterday he was off all meds and was happily out in the pasture. i went to go try a light ride today, and he looked happy and alert again. he was fine when i got on and walked, but did not want to pick up a trot. i called in my trainer and she told me to push him, and as he tried to pick up the trot he seemed to lose all balance...im not sure exactly what happened but his head was down, he was dragging his legs, and i honestly thought he was going to fall on top of me....he was such a good boy trying to keep his head straight to keep me balanced. its hard to verbalize what happened, but when he seemed semi stable i jumped down, and he was tense with his back end curled up and was shaking profusely. his temp is still normal, but hes having issues keeping balance while putting his head down to eat. stool/bloodwork from friday came back normal...noone is sure what to do. anyone have any ideas or seen anything like this?