Why do some Racehorses' tongues hang out of their mouths?

Answer 1

The tongues of racehorses sometimes hang out of their mouths as they run because they move their tongues to relieve the pressure of the bit. Sometimes their tongues hang out of their mouths out of habit or because they have a copper or sweet bit that causes them to salivate.

Answer 2

Many track trainers tie the horse's tongue to help them to breathe, basically. Some horses are prone to get their tongues up in the roof of their mouths and block airflow...not a good thing, right? So they tie the tongue to prevent this from happening. And in tying the tongue, it hangs out the side of the mouth.

Answer 3

Sticking their toungue out is a way of evading the bit. You are most likely being too rough with the bit, using it to MAKE him do something, instead of using the slightest touch to CUE him to do something. The drooling is very normal for horses to do when something is in their mouth, like a bit, espacially ones with tastes like copper, sweet iron, rubber, etc. Either lighten up and get a stainless steel gentle snaffle bit or get a bitless bridle, which I advise for many reasons but can't get into detail here.

Previous Answer:

Probablly because he is extremely hot and/or thirsty.

Answer 4

So that they don't swallow their tongues during a race.