Horse Anatomy: How Many Ribs Does a Horse Have?

Jessica McDaniel
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How Many Ribs Does a Horse Have?

When you count the ribs of a horse, you will find that horses have 19 pairs.

Since horses are mammals, they are warm-blooded, viviparous, and have mammary glands. Two things that are unique to mammals are the lungs and the skin. The horse has two lungs. They are located in its chest cavity. The horse has two lungs because it needs to breathe constantly.

They need to be able to breathe when they eat and drink water and during strenuous activity. The horse’s skin is made of hair for insulation, and it protects them against predators and weather elements.

How many legs does a horse have? Horses have four legs.

How many nipples does a horse have? Horses have mammae (singular mammary) mammary glands.

Horse Rib Shape and Structure

The design of the horse's ribcage protects all internal body organs from contact with the hard saddle and sharp spurs. However, the rib structure also allows flexibility for the spine and chest muscles.

A horse's ribcage is made up of 8 sternal ribs and 13 to 21 floating ribs on each side of the mid-section. The floating ribs attach to a flexible membrane called a thoracic diaphragm that separates the abdominal cavity from the thoracic cavity.

The horse's heart is located in the center of its ribcage and sits inside a bony cage to protect the vital organ. The membrane separating the left and right sides of the heart is extremely thin so the heart can "squeeze" and "squish" to pump blood.

The horse's lungs are attached to its rib cage so when a horse exhales, its ribs expand and contract to allow the lungs to inflate. Air is taken in through the huge nostrils and into the nasal cavities before being passed over the soft tissues of the nasal passages and larynx.

The horse's digestive system is attached to its chests and can be seen moving rhythmically up and down as the horse eats and digests. Since this system is a bit longer than the intestines, it tends to be on the outside of the rib cage, which is why you can often see your horse's ribs even when it's grazing.

Rib Structure Importance in Equine Wellness

The rib cage is the structure between the thorax and abdomen and has three bones • the scapula, the sternum and the thoracic vertebra. It is this bony rib cage structure that gives the horse its durability, mobility and stamina for running long distances. Inside the rib cage, the horse also has a complex system of air sacs and lung capacity not found in people, which is a unique respiratory system found only in animals that must breathe through their lungs.

The rib cage is important to the horse and its overall health as it serves as a vital protection for the heart which is located right behind the rib cage in mammals. The horse’s rib cage protects this valuable organ and allows access to a complex respiratory system.

A normal, healthy horse, will have:

13 fore ribs

12 Mid ribs.

33 hind ribs.

Structure is Importance for Horse Health

If you plan to own a horse you need to know what their anatomy looks like. This is important so you can check their body when in pain and know what to do to make them feel better.

Horses are mammals and thus their bodies are very similar to ours. except that they are larger, hairier and have long tails. But we do share the same parts in our body.

A horse has special adaptations to be able to support its own weight and those of their rider and all the other equipment that they may carry. One of these adaptations is the obvious number of ribs and chest cavity they have.

This allows them to carry large loads but thanks to their gut, which is always full, they don’t have to worry about their abdomen.

It’s similar to our upper and lower body. Our arms and legs are attached to our bodies by the trunk of our torso. A veterinary surgeon, seeing a horse, will have no problem identifying the different body parts and which part is damaged.

The ribs are attached to the spine, pelvis and sternum (breastbone) of the horse. They protect the tender organs of the horse, like the kidneys, lungs and liver. And also allow the muscles and tendons of the horse to attach themselves.

Horse Ribs Compared to Other Animals

As a mammal, a horse has the prominent feature of having four chambered heart, which is used to pump oxygen rich blood. The heart is protected by the rib cage, which is considered the most important organs of the horse.

In a horse, the chambered heart lies beneath the rib cage. A horse's rib cage is crucial to its respiratory function, which is used to suck air in to take in oxygen and releases carbon dioxide. The rib cage is an extensive and broad structure that includes twelve ribs in a pair with the left side having three pairs of ribs and the right side having a single pair of ribs.

A horse has a wide and deep chest to increase the lung capacity, thus providing oxygen to the heart. When a horse inhales, the ribs expand and make space for the lungs.


Horses have 24 ribs. They decrease in size from the last rib to the first. Horses are mammals, but don’t have 12 thoracic and 12 lumbar vertebrae. Horses have only seven thoracic vertebrae and five lumbar vertebrae. The thoracic vertebrae are easily seen with the lumbar vertebrae hidden by the loin muscles.

Did you know? Why do horses have 24 ribs? Or horse anatomy: how many ribs does a horse have? Really?

How many ribs does a horse have?