from the horse's mouth means directly from most ranking authority. The expression comes from
"In horse racing circles tips on which horse is a likely winner circulate amongst punters. The most trusted authorities are considered to be those in closest touch with the recent form of the horse, i.e. stable lads, trainers etc. The notional 'from the horse's mouth' is supposed to indicate one step better than even that inner circle, i.e. the horse itself. It is a 20th century phrase. The earliest printed version I can find of it is from the USA and clearly indicates the horseracing context - in the Syracuse Herald, May 1913: "I got a tip yesterday, and if it wasn't straight from the horse's mouth it was jolly well the next thing to it."" -http://www.phrases.org.uk/meanings/336400.html
The device that is place in the horses mouth is called a bit. It is a bar of metal used to steer the horse when riding.
It means you are scared of horses.
It's called a muzzle. Or just a horses mouth, depending how technical you want to get.
His mouth is called a 'mouth." But if you mean the combination of his mouth, lips and nose (basically everything below the eyes) then you mean the 'muzzle.'
lol that's a joke but the answer is your tongue and your teeth or 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
Their mouth....
fod
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.
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 horse has ingested a caustic chemical or plant...or the horse could have a number of diseases...vesicular stomatitis for example.
The bit
it is called a bit