Not only do we want to be a horse rescue site, but we want to be an owner educational site.
The majority of bits out there can be gentle OR harsh when in use; depending upon the skill of the rider’s hands.
(There are a few bits out there which are deliberately designed to inflict pain.)
If your horse constantly travels with its nose stuck straight up, or with its mouth open, or shakes its head much of the time, you probably have a bit problem.
Sometimes a the rider may find they are using a very mild bit with light hands and still have issues. But consider this, the bra that I might find comfortable isn’t always the one another gal wants to wear.
In the same vein, ALL horse mouths are made different.
If your horse is exhibiting any of these behaviors, first start with a knowledgeable person doing a teeth float. Often hooks are the culprit. If this does not solve your problem, you need to examine your bit choice.
This video offers a good overview of some common bits and exactly how they function in a horse’s mouth. (you might want to begin at 30 seconds or so)
(this horse was on a discussion forum where the owner was talking about the trainer saying he had major behavioral issues. WHY WOULD HE NOT BEHAVE BADLY IF HIS BIT WAS DOING THAT???)