Ok I have a 10 year old horse that I picked up re: breeding I started him on barrels and he has had some team roping training, but we cant get past the head shaking! We have had his teeth done by two different experts in the last 3 months. You can ride him in a halter or a o ring but you just dont have enough stop! I have tried hackamores and love the jim warner but the rawhide nose band he hates and tries to run through it! WE have even covered the rawhide and it is still to much pinch. I have went back to the basics on this horse that is not the problem. I am concerned that this is a habit for him but it only seems to do it with leg pressure to side pass or stop. Team roping he only shakes his head when you turn him to pull a steer or face up. I thought I had solved the problem when i took the chain chin strap away, he is very nose sensitive and mouth sensitive. I got a short shanked snaffle have been riding him in that went to run him on barrels at a jackpot today and he freaked out and went to shaking his head some of it is my nerves but there has to be a answer! I am convinced that there is some hackmore I could use but dont know does anyone have a idea. Little S does not work either. Thanks

Try to borrow someone's Perfect Bit and see if it will work. I'am using one on a figedy horse and it works on him. May not work all the time but is worth trying.

i tried that too short shanked didnt help, thanks though!!!!

We had a horse that did this too, we used hack on him that is just a leather piece and flat with long shanks, it worked really slick. I think we still have it and I can probably get you a picture of it. This was was extremly broke though and had a good whoa, maybe you need to put some of that back in him as well? Hope this helps?

Sounds like it's not in his mouth, so I don't think it has to do with what type of bit u use. U say he does it when YOU ask him to side pass or stop. Does he do this on HIS own when he is in a round pen(stopping)? try checking his physical condition out. Out in the poll, sore hocks, or in pelvic - stifle area. Some of it may be habit, but not all of it. I definitly would have a GOOD chiropractor check him out.

Does he do it in both directions are just going one way.? He may like was said be out some where.Watch a horse move loose in the pen and just watch.If they are soar they will move in one direction more than others.Also you might put him in a place like a lane and make him move around not stepping in front just drive him up into a corner and have some one shoo him back to you just force him to turn and watch what he does with no one on him.If he doesnt want to and goes one way more than the other on his on he is soar might be in his neck or shoulder We had one that was out in his knees and he wouldnt turn right.Your saddle could be putting pressure on that side also they will not want to turn into it.
Which way is worse or only is it one way?Thats a thought Its awfull hard to say when you cant see the horse.

thanks that is good advice I am on the search for a chiro in our area!

I ran into this same problem with a mare that I have. What I did was went with a chain bit with a very long purchase and took off the chin strap. She works like a champ now! Also I know you said you had her teeth done but have you checked for wolf teeth? These can be a huge problem especially in mares? Hope this helps. Also try a tiedown with a rope noseband and see if getting her nose sore helps at all?

After all medical has been checked as suggested, look at some of the english hackamores. They make some nice ones. Leather adjustable straps with wool lining. They have excellent contact but will not sore the nose. Some english bits do wonders for a "western" horse.
Hope you find the cause soon.
Kathy