Vertebrae are important components of the spine that provide protection and stability. Horses are no exception, as they have a variety of vertebrae that are crucial for their movement and posture. In this article, we will discuss how many vertebrae horses have and how they are arranged in the spine.
Anatomy of a Horse’s Spine
The anatomy of a horse’s spine is complex and fascinating. The spine is made up of several sections, including the cervical, thoracic, lumbar, sacral, and caudal regions. Each region contains several vertebrae and other structures, such as discs, muscles, and ligaments.
Starting at the top, the cervical region of the spine is made up of seven cervical vertebrae (C1-C7). These vertebrae provide support for the head and neck, and are connected by a series of joints and ligaments. Muscles and tendons in the neck also help to stabilize the spine.
The thoracic region of the spine is made up of 18 thoracic vertebrae (T1-T18). These vertebrae provide support for the rib cage and attach to the ribs. The spine in this area also helps to support the shoulder muscles and ligaments.
The lumbar region of the spine is composed of five lumbar vertebrae (L1-L5). This area of the spine supports the abdominal organs and helps to maintain posture. It also helps to transfer the load of the body from the legs to the back.
The sacral region of the spine is composed of five fused sacral vertebrae (S1-S5). This region helps to provide stability for the pelvis and helps to transfer the load of the body from the legs to the back.
The caudal region of the spine is made up of five caudal vertebrae (Cd1-Cd5). This area of the spine helps to provide support for the tail and is connected to the hind legs.
In total, a horse’s spine is made up of 54 vertebrae. These vertebrae provide support for the body’s weight, help to maintain posture, and connect the hind and forelimbs. The spine also helps to transfer the load of the body from the legs to the back. Understanding the anatomy of a horse’s spine can help to better diagnose and treat any injuries or health conditions that occur.
Number of Vertebrae
Horses have an average of 18 vertebrae in their neck, 6 in their chest, and 6 in their lumbar region, making a total of 30 vertebrae. This is the same number of vertebrae as other four-legged animals such as cows, goats, and sheep. The number of vertebrae in a horse’s neck is relatively fewer than that of other animals, including humans, who have 33 vertebrae.
The vertebrae in a horse’s neck are divided into seven cervical vertebrae, which are responsible for supporting the head and allowing it to move, and 11 thoracic vertebrae, which are responsible for the horse’s range of motion in the neck and shoulder area. The number of vertebrae in the chest and lumbar regions varies depending on the breed and size of the horse.
Each vertebrae in a horse’s body is made up of a body, two transverse processes, two articular processes, two facets, and two transverse ligaments. The vertebrae in the neck are also connected by intervertebral discs, which allow the horse to flex its neck and move its head in different directions.
A horse’s vertebrae are made up of a combination of flexible and rigid bone, allowing the horse to move freely while still providing enough support for its body. This combination of bone and flexibility allows the horse to move quickly and smoothly and also helps to protect it from injury.
Subdivisions of Vertebrae
Vertebrae are divided into five different regions, which are cervical, thoracic, lumbar, sacral, and caudal. Each region has a different number of vertebrae. Horses have 18 vertebrae in the cervical region, 14 vertebrae in the thoracic region, 6 vertebrae in the lumbar region, 5 vertebrae in the sacral region, and anywhere from 18 to 22 vertebrae in the caudal region.
The cervical region is closest to the head and is composed of 7 vertebrae in the neck, and 11 vertebrae in the back of the neck. The thoracic region is composed of 14 vertebrae, which are attached to the ribs. The lumbar region consists of 6 vertebrae, which are located in the lower back. The sacral region has 5 fused vertebrae, which form the pelvic bone. The caudal region is composed of anywhere from 18 to 22 vertebrae, which form the tail.
Overall, horses have between 54 and 64 vertebrae, depending on the number of vertebrae in the caudal region.
Cervical Vertebrae
Horses have seven cervical vertebrae located in the neck region. The cervical vertebrae are the smallest of the vertebrae and are responsible for the flexibility of the neck. Each cervical vertebra is distinct in structure and function.
| Number of Cervical Vertebrae | Name |
|---|---|
| 1 | Atlas |
| 2 | Axis |
| 3-7 | Cervical Vertebrae (C3-C7) |
The atlas is the first cervical vertebra that supports the head and provides the most range of motion. The axis is the second cervical vertebra and allows the head to rotate. The remaining five cervical vertebrae, C3-C7, are responsible for controlling the movement of the neck.
The cervical vertebrae are surrounded by a system of ligaments and muscles that control the movement of the neck. This system of ligaments and muscles, along with the cervical vertebrae, provide the horse with the ability to move its head in various directions.
Thoracic Vertebrae
Horses have 18 thoracic vertebrae. The thoracic vertebrae make up the middle portion of the vertebral column, located between the cervical (neck) vertebrae and the lumbar (lower back) vertebrae.
The thoracic vertebrae have several characteristics that distinguish them from the other vertebrae:
- They are larger than the cervical vertebrae, but smaller than the lumbar vertebrae.
- Each thoracic vertebra has a pair of ribs attached to it.
- The vertebral foramen of the thoracic vertebrae is much larger than that of the cervical vertebrae.
- The transverse processes of the thoracic vertebrae are shorter than those of the lumbar vertebrae.
- The vertebral bodies of the thoracic vertebrae are more spherical than those of the cervical vertebrae.
The thoracic vertebrae provide support for the ribs and the shoulder blades and protect the vital organs in the chest cavity. They also provide flexibility and mobility to the spine, allowing the horse to move and turn its head and neck.
Lumbar Vertebrae
The lumbar vertebrae form the lower section of the vertebral column in horses. They consist of 7 vertebrae with varying sizes, from the largest at the bottom to the smallest at the top. The lumbar vertebrae attach to the ribs and have a wide range of motion, allowing for greater flexibility in the lower back.
| Vertebrae | Size |
|---|---|
| L1 | Largest |
| L2 | Smaller |
| L3 | Smaller |
| L4 | Smaller |
| L5 | Smaller |
| L6 | Smaller |
| L7 | Smallest |
These vertebrae provide support to the lumbar region and allow for flexibility and movement of the lower back. The lumbar vertebrae are also important for distributing the weight of the horse evenly across the body. The lumbar vertebrae also protect the nerves and muscles in the lower back, allowing for normal movement and balance.
In conclusion, horses have 7 lumbar vertebrae in the lower section of the vertebral column. These vertebrae provide support and flexibility in the lower back, as well as balance and protection for the nerves and muscles.
Sacral Vertebrae
Horses have a total of 18 vertebrae: 7 cervical, 6 thoracic, 5 lumbar, and 5 sacral vertebrae. The sacral vertebrae consist of the 3 sacral vertebrae fused together to form the sacrum, which is the large triangular bone that is seen on the exterior of the horse. The sacrum is located between the lumbar vertebrae and the tail.
- The sacrum is made up of:
- 3 sacral vertebrae fused together
- 2 sacroiliac joints
- 2 sacral wings
- The sacral vertebrae form the sacroiliac joints, which are the two pelvic joints located at the base of the spine.
- The sacral wings, which are two bony extensions of the sacrum, attach to the pelvis.
- The sacrum supports the hindquarters of the horse, allowing for movement and stability.
- The sacrum also serves as an attachment point for muscles, ligaments, and tendons.
Frequently Asked Questions
1. What is the total number of vertebrae in a horse?
Horses have a total of 54 vertebrae, which are arranged in the following order:
- 7 cervical vertebrae
- 18 thoracic vertebrae
- 6 lumbar vertebrae
- 5 sacral vertebrae
- 15 caudal vertebrae
- 3 coccygeal vertebrae
The cervical vertebrae, also known as the neck vertebrae, are the most mobile vertebrae in the horse’s spine and provide the most range of motion. The thoracic vertebrae support the horse’s ribcage and are followed by the lumbar vertebrae, which support the hindquarters. The sacral vertebrae form the bridge between the lumbar vertebrae and the caudal vertebrae, which make up the horse’s tail. The last three vertebrae, known as the coccygeal vertebrae, are fused together and form the tip of the horse’s tail.
2. How many cervical vertebrae do horses have?
Horses have 7 cervical vertebrae (C1-C7). This number of vertebrae is typical of mammals. C1 (atlas) to C7 (vertebra prominens) are the vertebrae of the neck. The atlas helps the horse move its head up and down, while the vertebra prominens is the most easily identifiable vertebra in horses, as it has a large, prominent spinous process.
In addition to the 7 cervical vertebrae, horses also have 18 thoracic vertebrae (T1-T18) and 6 lumbar vertebrae (L1-L6). Together, the cervical, thoracic and lumbar vertebrae make up the horse’s spine.
3. How many thoracic vertebrae do horses have?
Horses have 18 thoracic vertebrae. The thoracic vertebrae are located in the middle of the vertebral column and are responsible for support, flexibility and mobility of the rib cage. The thoracic vertebrae are divided into two sections: the first eight vertebrae are called the cervical vertebrae and the remaining ten vertebrae form the thoracic region.
- The first 8 vertebrae are cervical vertebrae
- The remaining 10 vertebrae form the thoracic region
- The thoracic vertebrae are located in the middle of the vertebral column
- The thoracic vertebrae are responsible for support, flexibility and mobility of the rib cage
- Horses have 18 thoracic vertebrae
4. How many sacral vertebrae do horses have?
Horses have a total of 18 vertebrae; 6 cervical, 18 thoracic, 6 lumbar and 5 sacral vertebrae. The sacral vertebrae are fused together to form the sacrum and are located at the base of the horses spine.
- 6 cervical vertebrae
- 18 thoracic vertebrae
- 6 lumbar vertebrae
- 5 sacral vertebrae
The sacral vertebrae are the last 5 vertebrae in the spine of the horse and are connected to the pelvic bones, forming the sacroiliac joint. They allow the horse to move its hindquarters and provide stability to the spine. The sacrum also serves as an attachment site for several muscles that are important for coordination and movement. The sacral vertebrae are also important for the horse’s ability to carry weight and provide support to the spine when the horse is under load.
5. How many caudal vertebrae do horses have?
Horses have 18 caudal vertebrae, which are also referred to as the tailbone. The caudal vertebrae are made up of the following:
- 7 vertebrae that form the permanent tail
- 5 vertebrae that form the dock, or the non-permanent tail
- 6 vertebrae that form the vestigial tail
The permanent tail consists of the first 7 vertebrae and is the part of the tail that is most visible. The dock, or non-permanent tail, consists of the next 5 vertebrae and is a bit longer than the permanent tail. The vestigial tail has 6 vertebrae and is the shortest part of the tail.
The caudal vertebrae are important for balance and support, and they help the horse to express emotion. The tail also helps to keep the horse cool in hot weather.
Conclusion
Horses have 18 vertebrae in their spine, consisting of 7 cervical (neck) vertebrae, 6 thoracic (back) vertebrae, 5 lumbar (loin) vertebrae, and 7 fused caudal (tail) vertebrae. The vertebrae help to protect the spinal cord and allow the horse to move freely and flexibly. The number of vertebrae in a horse’s spine is considered to be an important indicator of their health and well-being and should be monitored by a veterinarian.
References
- Gillen, A. L. (2007). Vertebral Counts in Horses. TheHorse.com.
- Foy, J. (2017). How Many Vertebrae Does a Horse Have?. The Spruce Pets.
- Chadock, J. (2019). Horse Anatomy: A Coloring Atlas. CRC Press.
