Last Updated on November 8, 2021
It is no secret that horses like to eat a lot! But do you ever wonder how these magnificent equines manage to digest so much food? And how many stomachs do horses have?
Some mammals, such as cows, have more than one stomach. Horses eat pretty much the same diet as cows, so does this mean that they have two or more stomachs? Let’s take a look at horse digestion and find out!
How Many Stomachs Does A Horse Have?
The digestive system of a horse is incredibly sensitive and complicated. Equines have evolved over many thousands of years to be able to digest a large quantity of food known as roughage – this includes grasses, hay, and herbs.
The structure of the horse’s digestive system means they are classified as non-ruminant herbivores.
A horse is what is known as a trickle grazer – it eats very slowly, for long periods of time. In their natural environment, a horse will spend over 12 hours per day grazing. Imagine if you spent over half your day eating!
So, exactly how many stomachs do horses have? If they need to digest a lot of food, it would make sense for them to have more than one stomach?
In actual fact, these complicated animals only have one stomach!
Animals that only have one stomach, such as horses, are described as non-ruminant. Other animals, such as cattle, have more than one stomach and are called ruminants. Non-ruminant animals do not digest food efficiently in their stomachs, and horses rely on other intestinal organs to carry out the majority of the food processing.
How Big Is A Horse Stomach?
The stomach of a horse is relatively small for the size of the animal! The reason that it is so small is that the horse is a flight animal – it needs to be able to run away from prey at any time. A full stomach would slow the horse down, so the stomach is small and only holds a small amount of food at any one time.
The horse’s stomach is the smallest part of the equine digestive tract. It has a capacity of between 2 and 4 gallons. This is just one-tenth of the overall capacity of the entire digestive tract.
Of all domestic animals, the horse has the smallest stomach in relation to its body size. This means that horses should only eat small meals, which is why every horse owner knows to feed their horse ‘little and often.
What Does A Horse Stomach Look Like?
The stomach of a horse is a sac, with an entrance at one end and an exit at the other. It is roughly the size of a rugby ball and appears smooth on the outside. The inside of the stomach has a rough ridged appearance.
The entrance to the stomach attaches to the esophagus – this is the tube through which food travels from the mouth to the stomach. At the other end of the stomach food exits into the small intestines.
If you were to peek inside the stomach of a horse, you would see that it has two different sections. The upper part is smooth and white, and the lower part is darker and rougher.
The lower section is called the glandular region. This is where the digestive secretions are produced and where the food would normally sit.
The upper part of the stomach is called the non-glandular area. It is this area where gastric ulcers can develop. This normally occurs when acid splashes from the glandular area onto this sensitive tissue.
Horses are very unusual as their stomach is a ‘one-way’ system. Once food enters the stomach from the esophagus, it cannot leave again the same way. The sphincter at the entrance to the stomach is a one-way valve and will not allow the horse to regurgitate or vomit.
This can cause problems for the equine digestive system, particularly if part of the intestines become twisted or blocked. The stomach can quickly become distended with gas and liquid, which causes a condition called colic. Colic is a medical emergency for a horse, and you must always seek veterinary attention if you think your horse may be having digestive problems.
What Happens To Food In The Horses Stomach?
So, as we have already discovered, the food a horse eats must pass through the stomach. But what actually happens to the food while it is in there?
The functions of the equine stomach include storage of food, mixing of food, digestion of food, and controlled release of food into the small intestine. However, when it comes to digestion, the stomach has a very limited role to play.
The glandular part of the stomach releases digestive juices. These include pepsin, which is an enzyme needed to start protein digestion. The vast majority of horses will have very little protein in their diet, so most of their food digestion takes place elsewhere in the digestive system.
The stomach also releases an acidic substance called hydrochloric acid. It is this acid that can cause gastric ulcers. To help to prevent these from occurring, it is vital that a horse is not starved for long periods, otherwise, the stomach will quickly become empty and acid splashing can occur.
Mixing of food also happens in the stomach. The stomach contents are churned around by the movement of the horse and the stomach itself. The mixed food is then slowly released into the small intestine, where the digestive process continues.
So, as we have learned, a horse has just one stomach. However, the digestive system of a horse is highly adapted to eat a high-roughage diet, and the stomach is an important part of this. The stomach starts off the digestive process by mixing the food and secreting pepsin which begins to break down protein.
We’d love to hear your thoughts on the horse digestive system. Are you amazed at the amount of hay and grass your horse can eat? Or maybe your horse has problems with his digestion? Please add your comments below and we’ll get back to you!
Kate Chalmers is a qualified veterinary nurse who has specialized in horse care for the vast majority of her career. She has been around horses since she was a child, starting out riding ponies and helping out at the local stables before going on to college to study Horse Care & Management. She has backed and trained many horses during her lifetime and competed in various equestrian sports at different levels.
After Kate qualified as a veterinary nurse, she provided nursing care to the patients of a large equine veterinary hospital for many years. She then went on to teach horse care and veterinary nursing at one of the top colleges in the country. This has led to an in-depth knowledge of the care needs of horses and their various medical ailments, as well as a life-long passion for educating horse owners on how to provide the best possible care for their four-legged friends.
Kate Chalmers BSc (Hons) CVN, Dip AVN (Equine) Dip HE CVN EVN VN A1 PGCE