Why can't horses throw up?

Question

I know that they can't, but no one has ever really explained it to me.

Answer 1

They don't have the ability to throw up.  The esophagus doesn't have muscular action necessary to throw up, and if the food makes it to the stomach, the sphincter muscle at the stomach entry constricts tightly, making it virtually impossible for food to back up into the esophagus.

When food gets lodged in the esophagus, it is called choke.  If the foodstuff is lodged near the throat, it can get into the respiratory passages and discharge from the nose.  Since the esophagus has no reverse peristalsis (muscle action to move food back to the mouth), it has to be encouraged to move downward into the stomach.

ADD...I think where people get confused is when choke occurs.  In humans, choking occurs in the respiratory tract and we can't breathe.  In horses, it occurs in the long tube leading to the stomach (esophagus).  If food gets "stuck" in the esophagus, the horse will cough and sometimes any water he drinks will come out of the nostrils, or chewed food will not go down and be coughed out of the mouth.  It isn't vomiting.  In order to vomit up food lodged in the esophagus, a wavelike constricting and shortening action of the muscles in the wall of the esophagus would have to reverse direction to propell the mass of food back to the mouth.  The esophagus of the horse doesn't have this capacity.  And food already in the stomach can't get back out to be vomited, even if the esophagus could regurgitate it.  Basically, once food enters the horse esophagus, it has to keep moving in one direction.

Answer 2

they just don't have the gaging reflex, plus for horses don't really have a reason to throw up, like humans do it to get rid of the waste in there body but horses just p**p it out...lol

hope I helped... please best answer!

Answer 3

horses have a one way valve in their throat called an esophagus. think of it like a backflow valve in your house,food and water pass thru in one direction but when pressure is applied in the other direction it closes shut and this sometimes leads to colic or a gastric rupture if not taken care of in a hurry.when your horse has colic a vet or a person who knows what they are doing will pass a tube thru the nasal passage down the throat and thru the esophagus to the stomach to relieve pressure (this can be messy sometimes).after the back pressure is relieved a solution of water and mineral oil is pumped in to help lubricate the intestines and the blockage so it may pass thru easily.however a horse can discharge food and mucus thru the mouth and sinus tract and sometimes will be mistaken as a horse throwing up.

Answer 4

It's a one way road! Their muscle is so strong it cuts off any possibility of food coming back up. Also the angle isnt right for a horse to physically throw up.

Answer 5

Thay don't have the right muscles

Answer 6

Horses are unable to vomit primarily due to the muscles in the cardiac sphincter valve, the valve that leads into the stomach, being very strong. Those muscles are so strong that the stomach itself could rupture from the pressure before they'd be forced open.

The way a horses body is designed it is supossed to eat small qualities of food very often, such as when grazing. The stomach itself is very small, less than 10% of the total capacity of digestive system. Food generally stays in the stomach itself less than 15 minutes if the horse has been eating normally but is designed with the idea that more will be shortly following that food just passed on, at pretty constant flow of intake.

Basicly, everything in the digestive system is designed to keep everything through in one direction at a pretty fast pace, to make room for more roughage to be processed like a steady cycle.

That is the reason that horses do so much better if feed multiple small meals verses 2 large meals.

This site gives a pretty good description of how a horses digestive system works

http://ohioline.osu.edu/b762/b762_5.html

Answer 7

The muscle that acts like a one-way valve where the esophagus connects to the stomach actually does its job, unlike in humans where it can let food travel the opposite direction, back to the mouth. Another reason that horses can not vomit is because the esophagus is connected to the stomach at an angle where it is forced shut when the horses stomach bloats. This can cause colic when the horses stomach bloats, and untreated, the stomach will rupture and the horse will die.

Answer 8

Their esophagus actually works.