One of my bestfriends Lindsay has 3 horses two QH's and a rescued Boulonnais cross of some sort named Old John . He can be ridden and is a sweet boy and is gelded. Lindsay has three young children and lately Old John has ben acting out. Lindsay was riding him about 3 months ago working with John when he decided he wanted to forget all his former training and take of at a Canter. It shocker because it take alot to get Old John to trot. He would stop and they were riding on trails and he wasent responding at all. She said when she would try and pull back on the reins he would jerk his head and just about yank the reins right out her hands! This is not the worse part she tried once more to pull him back and he gave her three sharp bucks. Lindsay is great with horses and i have never seen her fall but he tossed her a good three feet she is guessing. He then went on his way. I asked her is he may have possibly been uncomfortable maybe the bit was in weird of his girth was twisted but she said she though of that too and she checked it once she caught old John and she said it all looked normal. They have owned Old John for 8 years (he is 18 years old) and have never EVER been a problem before. Their children have been on him (usually riding with Lindsay or Jack her husband) its a bit scary for her. She gave him a few days to cool off from the trail ride as he is not ridden everyday to begin with. This entire time he has been moody with all humans lol. Nipping at the kids head butting and just being a regular terror. Her husband decided to get on him the next time he was to be ridden as Jack is a big strong guy and figured he could control Old John easier. This time John did'nt buck, or canter, or anything like that. She did say he tried to bite Jack numeral times while tacking him up. But John simply would'nt move Lindsay said they tried everything nudging him to REALLY nudgig him with Jakcs feet, voice commands, Lindsay came out with a lead to try and lead Old John around and he would'nt move just tried to bite her and flattened his ears back. They did after that call the vet thinking maybe he was in pain. The put some time and money into to come out with the conclusion that he is perfectly healthy and just weird. She is here right now visiting and I decided it would be a good idea to ask any of you other fellow horse owners ideas or thoughts would be on the problem. Any advice would be great as well. Its crazy Old John went from a big marshmellow of a horse to a big boulder of a horse with an anger problem. Im not his owner i can't say how or why this would happened he is a well taken care of horse. I don't know I just know she is frustrated and upset. Like I said this horse is a rescue actually on his way to the butcher and she really doesent even want to Consider finding a new home for him to her this is no way at all that is going to happen.