StomachOne simple stomach, small for the size of the horse. So a horse eats small meals through the day. A horse cannot bring its food back up.
Small intestineA long tube of duodenum, jejunum and ileum. Enzymes digest starch, protein and fat here. A horse has no gallbladder, so bile runs in from the liver all the time.
CecumA very large blind sac that works as a fermentation vat. Its microbes break down the fiber of grass and hay.
Large colonThe biggest part of the tract. It has four sections, two ventral and two dorsal, and the fermenting of fiber goes on in it.
Pelvic flexureThe turn where the large colon folds back on itself. It comes between the ventral and dorsal halves. The tube is much narrower here.
Small colonNarrower than the large colon. It takes up water, and the droppings are shaped into balls here.
RectumThe last short length of the tract. The droppings wait here to leave the body.
ForegutMouth, esophagus, stomach and small intestine. Here the horse's own enzymes do the digesting.
HindgutCecum, large colon, small colon and rectum. Microbes ferment fiber here, which is why a horse is called a hindgut fermenter.
How this list was compiled: Every name checked on 2026-09-30 in two sources. The dog: S. Sisson, The Anatomy of the Domestic Animals (1914, public domain), https://archive.org/details/anatomyofdomesti00siss; the Merck Veterinary Manual's page for dog owners on the digestive system, https://www.merckvetmanual.com/dog-owners/digestive-disorders-of-dogs/introduction-to-digestive-disorders-of-dogs; Wikipedia, Monogastric and Cecum, https://en.wikipedia.org/wiki/Monogastric. The horse: Ohio State University Extension, The Gastrointestinal Tract of the Horse, https://ohioline.osu.edu/factsheet/1022; Rutgers Equine Science Center, The Basics of Equine Nutrition, https://esc.rutgers.edu/fact_sheet/the-basics-of-equine-nutrition/; the Merck Veterinary Manual's page for horse owners, https://www.merckvetmanual.com/horse-owners/digestive-disorders-of-horses/introduction-to-digestive-disorders-of-horses; and Sisson (1914), the horse. Licence: own work
The drawing: Drawn for this site on 2026-09-30 from plain geometry; nothing traced. Licence: own work
How it works
This horse digestive system diagram to label lays the tract out from left to right in the order feed passes through it, with the horse's head at the left. Numbers 1 to 7 follow that order.
Read the full guide
Horse digestive system word bank
Nine names, in alphabetical order: cecum, foregut, hindgut, large colon, pelvic flexure, rectum, small colon, small intestine, stomach.
The numbers that get swapped
Two names end in colon. Number 4 is the wide tube that runs down, turns and comes up again; number 6 is the narrower arched tube after it. Number 5 is only the tight turn at the bottom of 4. Number 3, the very large sac that slants down to the left, is not a colon at all. Numbers 8 and 9 end on the two brackets above the tract, not on an organ: each bracket names the half of the tract under it.
When marking, caecum is right on line 3, great colon on line 4 and floating colon on line 6.
The horse's head and the thin tube that leaves its neck, the esophagus, are drawn but have no number.
Questions and answers
Why can't a horse vomit?
The esophagus squeezes feed along in one direction only. Where it meets the stomach, number 1, a ring of muscle works as a one-way valve: feed and gas that have gone in cannot pass back up.
What are the four parts of a horse's large colon?
In the order feed passes them: the right ventral, left ventral, left dorsal and right dorsal colon. The pelvic flexure, number 5, is the turn between the two left parts. The worksheet asks for the large colon as one name, on line 4.
How is a horse's digestive system different from a cow's?
A cow ferments its feed in the rumen, before the small intestine; a horse ferments fiber after it. One extension fact sheet puts the stomach at about a tenth of a horse's tract by volume, against 70 percent in a ruminant.
Where does digestion begin in a horse?
In the mouth. A horse grasps feed mostly with its lips, then chews in a grinding, circular motion that breaks the feed small. Saliva wets each mouthful into a ball that is easy to swallow.