Why can't horses vomit?

Answer 1

They cannot vomit because the power of the cut off valve...

Answer 2

Horses cannot breathe through their mouths. They can only breathe through their nose. A horse can vomit, but if it does, it usually spells for a bad prognosis for the animal, because the food that is being regurgitated (along with the stomach acids) doesn't exit through the mouth, but through the nasal cavity, which in a horse, with their long faces, is very long and complex. It can't be a pleasant experience for the horse, and the area would be subject to a heavy bacterial infection as a result, leading to the rapid demise of the (already sick) animal.

By the way, the previous answer is incorrect: horses do not have four-chambered stomaches - the author is thinking of ruminants, such as cows, goats, and sheep. Horse stomaches are like typical mammalian stomaches (i.e., just 1 chamber), with some internal modifications that are not relevant to your question.

The first answer, regarding the angle at which the esophagus meets the stomach, is also a valid theory as to why horses cannot vomit.

The reason that a horse cannot breathe through its mouth is because the initial fold of the epiglottic cartilage (which is part of the larynx) lies on top of the soft palate (the soft part in the back of the roof of your mouth). In you or me, these two structures do not meet, allowing you to breathe through your mouth. In horses, however, the overlap of these two structures forms a temporary "seal" or "dead-end" in the back of the mouth that can only be broken when the horse is swallowing food or liquid. So as a result, when air enters the mouth in the horse, it has no where to go except back out the mouth - there's no way for it to reach the windpipe (trachea) this way.

Because of this limitation, if you ever look at a horse's nose, you'll find it has highly modified nostrils to allow it maximize the amount of air it can pull in, especially when it is racing at a full gallop.

Hope that helps!

(I teach at a vet school)

Answer 3

Horses can't vomit because their digestive system is built differently than ours and "the lower esophagus enters the stomach at an acute angle, which creates a one way valve. When the stomach is distended by food or air, pressure closes the valve and prevents reflux (vomiting)." This means that horses can't belch either and that is why an upset stomach generally called colic can be a very serious illness for a horse.

Answer 4

BASICALLY without all the vet mumbojumbo.. their stomachs are made up of 4 different chambers, with shut off valves infront of each one that only allows it to go one way. In the first chamber, there are actually a bacterial substance that takes the nutriets from the food, and their body actually takes nutrients from the dying bacteria,... so they don't really have the same stomach issues as people do with problems digesting food. Most of the reasons we vomit is from an issue with stomach acid or bacterial infection, which actually helps them eat! so there ya go.

Answer 5

Horses aren't ruminants (4 chambered stomach) They don't regurgitate food to digest it, instead it is fermented in their cecum where it is broken down and absorbed/digested