The organs of a horse where they lie, from the left side and from the right.
Horse Anatomy Quiz
Name Date
Tap any organ to read, rename or leave it out
1 of 7
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Write the name of each numbered organ.Answer key
Heart
Lungs
Trachea
Esophagus
Diaphragm
Stomach
Spleen
Left kidney
Small intestine
Left dorsal colon
Left ventral colon
Small colon
Rectum
Bladder
Liver
Right kidney
Duodenum
Cecum
Right dorsal colon
Right ventral colon
Drawn for this site on 2026-09-30 from plain geometry. Licence: own work.
Each numbered ring is a button. Use the arrow keys to move between them and Enter to choose. Names are read out in Study, and once a organ is answered.
HeartA hollow muscle of four chambers that pumps the blood. It lies low in the chest, its point just above the breastbone, a little more to the left than to the right.
LungsTwo large organs that fill most of the chest. One lies on each side of the heart. Air reaches them through the trachea, which divides into a bronchus for each lung.
TracheaThe windpipe, held open by rings of cartilage. It runs from the larynx down the neck to the lungs.
EsophagusThe tube that carries food from the mouth to the stomach. It runs down the neck beside the trachea, through the chest and through the diaphragm.
DiaphragmA sheet of muscle that divides the chest from the belly. In the horse it slopes steeply, from under the loin forward and down to the breastbone.
StomachSmall for the size of the horse. It lies high in the belly, behind the diaphragm and mostly to the left of the midline.
SpleenA long curved organ on the left, close against the stomach. It holds a store of red blood cells.
Left kidneyOne of the two kidneys, which make urine. The left one is bean-shaped and lies under the last rib and the front of the loin.
Small intestineThe long narrow part of the gut. The horse's own enzymes digest its food here. Its coils lie high in the left flank, mixed with those of the small colon.
Left dorsal colonThe third part of the large colon. It runs forward above the left ventral colon, from the pelvic flexure to the diaphragm.
Left ventral colonThe second part of the large colon. It runs back along the floor of the belly to the pelvic flexure, where the colon turns and narrows.
Small colonThe narrower gut after the large colon, leading to the rectum. The droppings are shaped into balls in it.
RectumThe last part of the gut, about a foot long. It runs through the pelvis to the opening under the tail.
BladderThe bag that stores urine until it is passed. It lies on the floor of the pelvis and reaches forward as it fills.
Right side 6
LiverThe largest gland in the body. It lies slanting against the diaphragm, mostly on the right, its highest part up by the right kidney. A horse has no gallbladder.
Right kidneyLies farther forward than the left kidney. It sits under the last two or three ribs. It is shaped like the heart on a playing card.
DuodenumThe first part of the small intestine. It runs up the right side from the stomach, past the liver to the right kidney, and bends round the base of the cecum.
CecumA great blind sac shaped like a comma, where microbes ferment fiber. Its base lies high in the right flank, and its body runs forward and down toward the floor of the belly.
Right dorsal colonThe fourth and last part of the large colon, and the widest. It runs back above the right ventral colon toward the small colon.
Right ventral colonThe first part of the large colon. It begins at the cecum and runs forward along the floor of the belly to the breastbone.
How this list was compiled: Every name checked on 2026-09-30 in two sources. S. Sisson, The Anatomy of the Domestic Animals (1914, public domain), for where each organ lies, https://archive.org/details/anatomyofdomesti00siss. The Merck Veterinary Manual's pages for horse owners on the digestive system, the heart, the lungs and airways and the urinary system (normal anatomy only), https://www.merckvetmanual.com/horse-owners. 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/. Wikipedia, Equine anatomy, https://en.wikipedia.org/wiki/Equine_anatomy. Licence: own work
The drawing: Drawn for this site on 2026-09-30 from plain geometry; nothing traced. The outline keeps the proportions of this site's own horse drawings. Licence: own work
How it works
This horse anatomy quiz shows the organs inside a standing horse from its left side, then from its right. The two sides differ: the stomach and spleen lie on the left, the liver and cecum on the right.
Read the full guide
Left side
The chest holds the heart, low behind the front leg, and the lungs above it. The diaphragm slopes from the loin forward to the breastbone. Behind it lie the stomach, the spleen, the left kidney, coils of small intestine and small colon, and the two left parts of the large colon.
Right side
Switch to Right side. The liver lies against the diaphragm. The cecum fills the flank, wide at the top. The right ventral colon starts from it along the floor of the belly, and the right dorsal colon lies above. Press Quiz me to name each organ yourself.
The two kidneys do not match: the left is bean-shaped; the right is shaped like the heart on a playing card and lies farther forward.
Questions and answers
Where is a horse's heart?
Low in the chest, between the third and sixth ribs, with its point just above the breastbone. A little more of it lies to the left of the midline than to the right.
Which side is a horse's cecum on?
The right. Its wide base lies high in the right flank, and its body runs forward and down to a point on the floor of the belly, behind the breastbone.
How many parts does a horse's large colon have?
Four, in this order: right ventral, left ventral, left dorsal and right dorsal. It doubles back on itself at the pelvic flexure, between the two left parts.
Which organs are on a horse's left side?
The stomach, the spleen, the left kidney and the two left parts of the large colon, with coils of small intestine and small colon high in the flank.