As in "I am so hungry, I could eat a horse"- means you are extremely hungry- since a horse is VERY big.
By looking a horse in the mouth, you can tell their age and whether or not they're in good health. But if you get a horse as a gift, you should be happy to have a horse and not question what shape they're in.
Mess
I think you mean "no great snakes," and it means "no big deal."
Sparrows and Swallows eat horse flies
Cugars and moution lions also do and americans that eat horse meat
A cliche
Nothing. The correct idiom is "get OFF your high horse," meaning stop acting so conceited as if you are above everyone else.
It's not an idiom, it's a saying. If the horse is blind, it can't see either the nod or the wink, so they'd mean the same thing to the horse. You nod when you're agreeing and you wink when you're sneaking around with something.
Getting on your high horse means that you are looking down on someone with a haughty or superior attitude.
It can mean to eat a huge amount, more than you normally would.
To eat dirt simply means to endure or accept insults or bad treatment.
"To eat like a horse" means to eat a LOT of food.
Eat your hat: a statement made when you are positive that something will happen, as in "I'll eat my hat if our team loses this game."
Eat the freaking horse!
The horse and carriage are obsolete as modes of transportation, so this idiom means that something has become obsolete or passed out of common usage.
That's not an idiom. It means just what it looks like -- something is fit for you to eat.
One such idiom is "Don't look a gift horse in the mouth."