How many stomachs does a horse have? How many chambers does a horse stomach have?
As non-ruminant herbivores, horses have a unique digestive system.
It affects how they eat and what is safe for them to eat.
In this article, I will share facts about the horse digestive system, explain the difference between ruminants and non-ruminants, and answer some related questions about horse digestion.
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All About the Horse Digestive System
Horses are non-ruminant herbivores, so they have plant-based and high-grain diets. Their digestive tract or digestive system has the mouth, esophagus, stomach, small intestine, and large intestine.
How Many Stomachs Does a Horse Have?
The horse only has one stomach with a single compartment or chamber. It is the smallest part of their digestive system, making up just 10% of the total volume.
The horse’s stomach only holds around 2 - 4 gallons of material, which is roughly the same as 8 cartons of milk. They have a very small stomach capacity in comparison to their body size.
Because the horse’s stomach is so small, it supports a slow rate of intake of forage several times a day. Although the stomach only has a single chamber, this chamber has two distinct regions:
- Glandular region - this region has all the cells that produce stomach secretions like hydrochloric acid and peptidases to break down proteins. It also makes mucus and bicarbonate to protect against the low pH of the acid
- Non-glandular region - this region does not have any of the protective features of the glandular region and is more prone to the formation of ulcers as a result
The functions of the stomach are mixing and churning to break down food, food storage, and the slow release of food into the small intestine.
Here is a video that explains more about the horse's digestive system:
https://www.youtube.com/watch?v=8lqk7igz9L4
How Many Chambers Does a Horse’s Stomach Have?
As mentioned above, a horse has a single-chambered stomach. Because of this is that horses cannot store large amounts of food.
They need to be able to turn food into energy quickly to support their high activity level.
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Parts of the Horse Digestive System
The horse digestive system consists of the mouth, esophagus, stomach, small intestine, and large intestine. This chart highlights each part and its function in horse digestion
|
Digestive System Part |
Function |
|
Mouth |
Includes the teeth, tongue, and salivary glands that release saliva to break down food. |
|
Esophagus |
The tube connecting the mouth to the stomach, once the food leaves the mouth it is squeezed down the esophagus to the stomach in a process called peristalsis |
|
Stomach |
Mixes and stores food. It controls its release into the small intestine. It also secretes peptides to start protein digestion. Churned food moves from the stomach to the small intestine |
|
Small intestine |
The small intestine is 70 ft long and makes up 30% of the digestive system. It absorbs nutrients and digests carbohydrates, protein, and fat. |
|
Hindgut |
The hindgut is the last part of the digestive system and consists of the cecum, large colon, small colon, and rectum. Its main function is to digest the fiber that the horse gets through its diet |
All of the parts of the digestive system work together to ensure that your horse gets proper nutrition.
When food cannot be properly digested, your horse will not have enough energy and be more prone to illnesses like impaction colic.
Interesting Facts About Horse Digestion
Now that you know about the stomach, here are some other cool facts about horse digestion that will get you thinking.
Fact 1: The Horse’s Esophagus Only Goes in One Direction
This means that food cannot come back up the esophagus and that horses cannot vomit.
Since they cannot vomit, a horse choking could be a fatal accident. Have someone on your barn staff that knows how to help a choking horse.
Always seek a veterinarian's help immediately for a horse with choke. It is an emergency that requires veterinary intervention.
I have been at the barn while a horse was choking, and although I did not witness the experience myself, I heard about it afterward and it is something I would not wish on any horse enthusiasts.
Fact 2: Horses Do Not Have Gallbladders
Because the horse’s digestive tract is designed a certain way to fit the structure of their body, they do not have room to fit a gall bladder.
Ohio State University states that "The liver continually secretes bile to assist in fat digestion. Amazingly, horses can digest and absorb relatively high levels of fat in their diets despite not having a gallbladder."
READ MORE: Can a Horse Carry a 200 Pound Person?
Fact 3: The Microbes and Bacteria in the Horse’s Gut Adaptto the Food They Eat
When a horse’s diet is changed suddenly and changes are not introduced gradually, the microbes and bacteria cannot ferment the new food, which leads to colic.
Horses must have all new food introduced a little bit at a time so that their body has enough time to prevent digestive disturbances and so they do not fall ill.
Fact 4: When a Horse’s Stomach is Empty, the Stomach Acid Can Break Down the Stomach Lining
This is also a cause or possible cause of gastric ulcers in horses and why horses need small meals several times a day so that the stomach is never empty.
Jennifer MacNicol, a PhD candidate at the University of Guelph says - "If acid splashes up, or their stomach is empty, it can really damage a horse’s stomach,”
This is why horse experts recommend that horses have constant access to roughage such as hay. It helps prevent an acidic stomach and gastric ulcers.
Fact 5: Horses Can Only Chew On One Side of Their Mouth At a Time
They use a slanted outside to inside motion of their teeth to grind up the food, which only allows them to use one side of their mouth at a time.
The matching surfaces of the upper and lower cheek teeth work together to break down food so that it can pass through the esophagus.
Horses are fascinating creatures. Now that you know about the stomach and how the horse digestive system works, let’s explore the differences between ruminant and non-ruminant animals.
This video from Equine Veterinarian Dr. Ross Teitzel explains more about the horse's digestive system.
https://www.youtube.com/watch?v=tuzTJ77IQAY
Ruminants vs Non-Ruminants: What’s the Difference?
Animals are usually divided into two categories based on their stomach structure: ruminant and non-ruminant. In most cases, ruminant animals are herbivores while non-ruminant animals are omnivores and carnivores.
The following chart highlights the differences between ruminators and non-ruminators.
|
Ruminants |
Non-Ruminants |
|
Animals that chew and spit out their food more than once and digest it in different stomachs each time |
Animals digest all of their food in one simple stomach. Food does not ruminate because it does not have to be redigested |
|
Usually herbivores |
Usually omnivores or carnivores |
|
Complex stomach with four digestive departments: the rumen, reticulum, omasum, and abomasum |
One stomach with one compartment divided into glandular and non-glandular regions |
|
Long digestive process and system |
Short digestive process and system |
|
Do not produce peptides to digest protein |
The stomach makes peptides to digest protein |
|
Have to blunt canines to break up plant materials |
Have two sharp canines to tear apart meat and other tough materials |
|
Premolars and molars move in a lateral direction |
Premolars and molars move in a vertical direction |
|
Produce more saliva that has no enzymes to digest carbohydrates |
Produce less saliva that contains enzymes to digest carbohydrates. Participate in enzymatic digestion/ |
|
Regurgitate their food |
Do not regurgitate their food |
|
Have a large liver |
Have a small liver |
|
Take a long time to digest plant material |
Have a shorter digesting time compared to ruminant animals |
|
Digest all of the plant carbohydrates for energy, including cellulose |
Do not digest cellulose because they get carbohydrates from other sources |
|
Cattle, sheep, goats, buffalo, deer |
Humans, rabbits, dogs, pigs |
|
Can have reverse peristalsis or esophagus motion |
Cannot have reverse peristalsis |
|
Need more fiber |
Need less fiber |
Ruminants and non-ruminants are so different from each other because they have unique dietary and energetic requirements that are necessary for them to survive
The only similarities between these two types of animals are:
- They both have a complete digestive system consisting of the mouth, esophagus, stomach (or many stomachs), large intestine, and small intestine
- Both eat meals throughout the day and consume energy from the food they eat
At the end of the day, all animals can digest food because they need food to survive, some just do it differently from others.
FAQs
Do horses have small stomachs?
Horses have small stomachs relative to their size with a small stomach capacity. Their stomachs can only hold 2 - 4 gallons altogether. This is why do better with small quantities of food spread throughout the day.
How many stomachs does a donkey have?
Donkeys have one stomach with a non-glandular and a glandular region. Donkeys are non-ruminants with a similar digestive tract to horses.
How many hearts does a horse have?
Horses have one heart because they are mammals.
Conclusion
How many stomachs does a horse have? Horses only have one stomach and they can only digest small portions of food at a time. If they eat too much, they can get colic.
Horses have a very interesting digestive process, and they cannot vomit up food so choking is a danger.
Horses are some of the only non-ruminant herbivorous animals, and ruminants and non-ruminants are very different from each other.
How many stomachs does a horse have? Please share your opinion on this topic below!
References
- “Maintaining a Healthy Equine Digestive Tract: Mouth and Esophagus.” Kentucky Equine Research, 31 Jan. 2012, ker.com/equinews/maintaining-healthy-equine-digestive-tract-mouth-and-esophagus/. Accessed 8 May 2022.
- “The Gastrointestinal Tract of the Horse.” Ohioline.osu.edu, ohioline.osu.edu/factsheet/1022. Accessed 8 May 2022.
- “Make Horse Feed Changes Gradually.” Kentucky Equine Research, 16 Sept. 2011, ker.com/equinews/make-horse-feed-changes-gradually/#:~:text=Start%20by%20mixing%20a%20small. Accessed 8 May 2022.
- “Straight from the Horse’s Stomach | Ontario Agricultural College.” Www.uoguelph.ca, www.uoguelph.ca/oac/horses-stomach#:~:text=Like%20humans%2C%20horses. Accessed 8 May 2022.
- “Discussion of Ruminants vs. Non-Ruminants.” Kb.wisc.edu, kb.wisc.edu/dairynutrient/414RN/page.php?id=55808.