Did you know…
…horses cannot breathe through their mouths?
In horses, the soft palate covers the opening of the larynx, except when swallowing. This prevents them from inhaling food but also prevents air from flowing from the mouth to the throat. This way, nasal and oral cavity are separated.
I can also tell you horses cannot vomit. The muscular sphincter that is located at the entrance of the stomach is much stronger in horses than in other mammals, such as humans. This sphincter only opens if stimulated in the right way: by food coming down the esophagus and not when food is trying to get back out of the stomach. The stomach in horses is also positioned in such a way that it presses against the sphincter when it is full, thus pressing it closed and preventing food from leaving the stomach. All of this makes it impossible for a horse to throw up. This may seem like it would come in handy, but vomiting can be a life saving mechanism in some cases, one that horses clearly lack.