Something that comes "from the horse's mouth" is firsthand information directly from the ultimate source of the information rather than secondhand through hearsay. As for why it's called the horse's mouth, this goes to horse racing. Because of the stakes, people will always try to get some leg up on which horse to bet by seeking insider sources. The closer one gets to the actual horse (like say stable-hands), the more reliable the information's supposed to be. Take this notion to its logical extreme and one comes up with the idea that the best source of knowledge about the horse would be the horse him/herself, although barring someone like Mister Ed, actually getting useful information is unlikely. Thus the idiom indicates a source of information that is beyond reproach because it's pretty much beyond what anyone should be able to reach.
it means Close your mouth. AKA stop talking.
win you my mom
person who shoes horses
It is short for 'come in mouth' or 'ejaculate in mouth', referring to fellatio (oral sex, penis to mouth).
it means mouth
It is a possibly, but there are no reported cases of it in horses.
A plain snaffle or a happy mouth.
A "bit" is a metal link across a horses mouth used when riding. The term normal means that someone has a grasp some information on something and is following it through
fod
Their mouth....
A horses bars are the toothless spaces in it's mouth, where the bit is placed.
A bit is metal bar that is on the bottom of the bridle. This fits inside the horses mouth, behind the teeth, where there is a gap.
The part of the tack (harness) that fits in the mouth of a horse is the bit.
The horse has ingested a caustic chemical or plant...or the horse could have a number of diseases...vesicular stomatitis for example.
I'm not familiar with a 'headpiece' but I think you mean the bridle. This is used to control the horse's head and keeps the bit in the horse's mouth.
The bit
it is called a bit