about 10 days ago at a race I came off first and my horse broke in two, launched me. Then bucked for 5 minutes after.
I haven't been back on him him since, went to the vet today, unfortunately the vet found no lameness. Did back X-rays, no sign of kissing spine. The next step is scope for ulcers. Which I'm making an appointment for that, hopefully this week. Haven't ruled out my saddle but didn't find anything obvious. 

any other suggestions? This is abnormal for this horse, he's been known to crow hop when feeling good but never like this or during a run. I'm feeling pretty defeated and don't believe he was just being an ass. 

Have a chiropractor work on him.  Sternum comes to mind

Also, try switching girths. If you have a neoprene, switch to felt or vice-versa.

Although not barrel racing, a friend of mine went through something similar. Her 11 year old gelding that she had owned since he was a weanling started bucking with her. She landed in the hospital twice. She spent a bunch of money on vetting and found nothing. Her horse's issue ending up being a leadership one. She did almost all of his training and was babying him too much. She sent him off for 30 days  and he learned what it meant to be a horse in work and she  learned how to treat him like a horse. No bucking since then but he will still test her. 

I'm not saying this is your issue but something to think about?

My mare did this to me one day in practice - crow hopped after the first, didn't think anything of it, just whooped her up and went on.  Next time thru, she broke in half after the second - she has never bucked with me, i've had her about 7-8 months. She is a rescue and I don't know much about her history.  Fortunately, I did not come off and we went on about our merry way, but it was pretty sketchy for a little bit!  I made her work - hard.  She hasn't done it again, it's been a couple months now and she's been her normal self.  Maybe she just had a day  - I don't know.what happened or why and hopefully it doesn't happen again.

I know this probably is not helpful, but maybe he just had a bad day or he needs reinforcement that you are the leader of this "herd" - Best of luck to you!! 

This is interesting you say this. I've had issues with my 4 year old bucking and kicking out with me (just generally bad attitude when asking her to work). Started when she was a 3 year old. I tried to change everything to make her happy and vetted her. Sent her to the trainer and while she gave a little attitude at first she never bucked or kicked out. Got her home and within 2 weeks she was back to testing me. Spoke to an animal communicator (as I'd done everything else) and she said my mare sees me as mom (I've had her since weaning), knows I love her, and doesn't think I'll make her do it if she doesn't want to.  

Now my goal is to ride her more and when I'm riding don't let her get away with anything. When she starts the attitude I've got to get onto her and remind her who is the boss. 

Insurance. Take a length of sturdy string like nylon. Run it snugly up between his top gums and upper lip, tie it around his poll. Make sure it's tight enough that he can't work it off. Now tie a string from poll to saddle horn. Make it loose enough that he can't get his head down to buck. If he snatches his head down, the string will hit his gums like a twitch. He will pull head back up. 

Thank you for all your suggestions I really appreciate it.

I had him worked on the day after, the lady said his pole was out, his back was locked up and his hamstrings were tight. She didn't mention the sternum but I will for sure ask about it and have her work on that next time. 

I've been using a mohair cinch, I was wondering about changing that out to see. I thought about saddling him tonight and flagging him off another horse to make him move out, see if he bucks with the saddle on, he didn't when we ponied him the other night, but he wasn't saddled. 

I raised this horse, he's always been a ****, but he's never bucked like he did the day he got me. I am probably too soft on him. He's always done his job so I haven't got after him much. He spent 60 days as a 4 year old being cowboyed on. I am considering sending him back to the guy for a tune up, see if he pulls anything on him. I'm not against a good ass kicking if one needs it. 

Knock on wood I've never dealt with ulcers, would they make him blow up? He was fine to saddle and warm up that day. Is gastrogarud the only option to heal them? I know it's pricey but if he does have them, I'll spend it to clear them up. 

I'm scared and worried I'll never mentally get past this to run him competitively again, will I ever trust him again? I was finally having fun and enjoying barrel racing again. 

I'm not sure I'm brave enough to try this, but I do see the logic behind it. 

His stifles might have caught.  That will scare the **** out of some of them.  

Is that something that should of shown on the lameness exam? 

How long have you had him and how old is he?  Fitness and age will cause a back to change and so saddle that fits fine in July may not fit well in January or vice versa  nor does a saddle that fits at 8 sometimes fit at 11...might also take your saddle in to have the tree checked.

He is 8 and I raised him. We've looked over my saddle and not found anything obvious but I haven't taken it to a saddle maker to have it checked.

I would go ahead and put him on Gut X or Jeremiahs Ulcer Repulser (omeprazole doesn't treat hind gut ulcers), check saddle fit and pad..he could have been pinched.. get him adjusted and make sure they check sternum, maybe get a second opinion on hocks and stifles. 

I have an appointment to get him scoped for ulcers on Tuesday. I'm torn between scoping to know or just treating, but where this happened out of the blue I feel like I need answers. 

Go ahead and scope but I would treat either way. Hind gut ulcers don't show up with a scope. 

Have you cleaned his sheath  and checked for a bean lately?

Since you already have appt. thats a great start and in the meantime I'd toss your saddle up on him with no pad and check fit as well as taking it to a saddle maker or repair place and have them check the tree for any issues. Also stand up high above him with someone holding him squared up to make sure his back,hips and shoulders are as symectrical as possible.  That 's how I realized my old bay mare had one shoulder quite a bit larger than the other, had to get a larger gullet and pad the smaller shoulder for her.  Some horses will put up with pain and other than not clocking you never really feel a thing, or a slight offer to look off as you ride into the pen, maybe a slight chAnge in how they use themselves in the turn (most of which I chalked up to him getting older and a little slower) until the issue is so bad they finally save themselves.

Some great suggestions on here, and I wanted to say change one thing at a time.  That way you know what works and what doesn't. 

And with ulcers if you suspsect them, treat them, through they vet.  Nothing treats them like what a vet can give you. 

Thank you! It's hard to not change a bunch at once! 

I did saddle him last night and chased him around the arena on another horse. He crow hopped when he kicked to a lope but nothing like the day he got me, it seemed more like he was playing than pain. When I threw the saddle on and was cinching him he was yawning and super relaxed. I haven't ruled out my saddle but I would think he should show some discomfort. 

I'm going to do some round pen work between now and when he gets scoped. See how he acts. I know I need to get back on him eventually but I'm still pretty beat up, apparently I don't bounce back like I used to.