Key Insights
  • Roach back, or equine kyphosis, is an abnormal upward curvature of the spine between the withers and haunches
  • Congenital cases arise from developmental abnormalities in utero, while acquired cases follow injury or arthritis
  • Mild cases are often cosmetic, but severe deformities may cause pain, mobility issues, or neurological deficits
  • Diagnosis involves physical and neurological exams, with imaging such as X-rays or myelography for confirmation
  • Treatment focuses on pain management, physical therapy, and proper saddle fit rather than surgical correction
  • Most mildly affected horses can remain in work, though severe spinal deformities carry a guarded prognosis
  • Preventing injuries, maintaining conditioning, and supporting broodmare health reduce acquired case risks

Roach back, or equine kyphosis, is an uncommon but noteworthy spinal condition. It is characterized by an upward arching of the back, disrupting the natural concave curve between the withers and haunches.

This structural anomaly stems from malformations in the vertebrae (spinal bones) and may vary in severity, ranging from purely cosmetic to cases where pain, limited mobility, and even neurological issues are present.

While some horses are born with this condition, others develop it later due to injury or other musculoskeletal challenges. Understanding the complexity of this condition requires insight into spinal anatomy, causes, symptoms, diagnostic approaches, and treatment options.

Read on to learn more about the key aspects of roach back, including its impact on equine health and performance, along with strategies for diagnosis and management. Whether congenital or acquired, addressing roach back effectively can support the welfare and performance of affected horses.

Roach Back in Horses

Roach back, also known as kyphosis or kyphoscoliosis, is a conformation defect where there is an abnormal curvature of the spine causing the horse’s back to arch excessively upward, creating a hunched appearance. [1][2][3][4][5]

Kyphosis is caused by a malformation of the vertebrae (spinal bones) in the middle of the horse’s back that results in a flat or convex line between the withers and the haunches instead of the familiar concave curve. [1][2][3]

Many cases of roach back in horses are merely cosmetic defects, but severe malformations may be associated with pain, mobility issues, and neurological symptoms. [2]

Spinal Anatomy

The horse’s spine is a complex mechanical and nervous system structure that is fundamental to all movement and sensation below the head. The spine is made up of a stack of rounded bones called vertebrae which are connected by soft tissue intervertebral discs. The vertebrae and discs work together, allowing lateral and  vertical movement while also protecting the critical spinal cord. [6]

The number of vertebrae for each horse depends on the individual morphology of the animal, but it ranges from 51 to 58, with an average of 54 vertebrae in a fully grown adult horse. [6]

The equine spine consists of five sections: [6]

  • Cervical spine: There are 7 cervical vertebrae in the horse. The vertebrae give structural support to the horse’s neck, starting at the back of the skull and ending at the shoulder.
  • Thoracic spine: The next 18 vertebrae that sit above the rib cage and form the withers and part of the back. In some horses, there is an extra thoracic vertebra, creating a longer back. Each thoracic vertebra anchors a set of ribs.
  • Lumbar spine: The 6 vertebrae running from the back to the highest point of the hindquarters, connected to the pelvis. Some horses, especially Spanish Mustangs and Arabians, have fewer lumbar vertebrae.
  • Sacral spine: Consists of 5 fused vertebrae that form the sacrum. This structure slopes from the hindquarters to the top of the horse’s tail. This portion of the spine is not mobile like the rest of the spine is. It functions to anchor the hind legs and as a point of attachment for the muscles and ligaments of the pelvis.
  • Caudal spine: The caudal spine consists of between 15 and 25 small vertebrae that sit in the fleshy part of the tail. This part of the spine directs the motion of the tail.

The vertebrae of horses with roach back may be wedge-shaped or otherwise deformed. They are not uniform, are often misaligned, and because of their deformity may cause damage to the intervertebral discs. This causes the spine to curve in an unusual shape since the vertebrae do not sit neatly side by side. [1][2][3][5]

Causes

Roach back in horses can be a congenital condition or it can develop after an injury or secondary to other musculoskeletal issues. [4]

The mechanism behind congenital equine kyphosis has not been fully characterized, but it is a developmental abnormality that arises while the fetus is in utero. Possible contributing factors may include: [2]

  • Genetics
  • Dietary imbalances
  • Exposure to toxins
  • Hormonal changes
  • Environmental causes
  • Oxygen deficiency
  • Increased dam body temperature

In cases of acquired roach back, damage caused by injury or trauma changes the shape of the vertebrae. For example, structural changes to the vertebral column may occur secondary to a spinal fracture or arthritis. [8]

Additionally, other physical conditions such as flexural limb deformities or other musculoskeletal issues can affect the horse’s posture, resulting in roach back over time if the abnormalities are not corrected. [1]

Symptoms

The characteristic symptom of roach back is an abnormal topline. [1]

In a normal horse, the back is highest at the withers and then slopes down and back up towards the haunches, forming a gentle concave line along the spine. Horses with roach back are not concave between these two points. Instead, they either have a flat or slightly convex line giving them a hunched appearance. [1]

Horses with more severe cases of roach back, especially where the bones are impinging on the spinal cord, may develop neurological symptoms such as weakness and clumsiness. [7]

Foals born with this condition may have worsening deformity as they mature. [2]

Horses that are born with roach back are less likely to develop additional symptoms as the body adapts to the spinal deformity while the horse is growing. [4] In cases of acquired roach back, the horse may show signs of pain related to osteoarthritis. [4]

Severity

The severity of roach back depends on whether the horse exhibits signs of pain and physical or neurological deficits. [3]

Mild cases of roach back are primarily cosmetic. Horses with mild or moderate roach back are often successful riding horses with appropriate saddle fitting and monitoring.

Dr. Jennifer Skaggs, DVM

“Kyphosis, commonly referred to as 'roach back,' is a structural abnormality of the spine that can affect a horse’s comfort and performance. While some mildly affected horses remain sound and usable, others may experience back pain, limited flexibility, or compensatory issues elsewhere in the body. Each case must be evaluated individually to determine the best course of management.”

— Dr. Jennifer Skaggs, DVM
Equine Veterinarian

 

More severe cases of roach back are accompanied by pain, impaired mobility, or changes to neurological function. [3] Severe cases of equine kyphosis are often associated with mobility issues in the pelvic limbs (the hind legs), often as a result of impingement of the spinal cord. [3]

Additionally, horses with roach back may also have other malformations of the spine including hemivertebrae, where the vertebrae are wedge-shaped, or scoliosis, where the spine deviates to the side. [3]

Neurological dysfunction typically occurs if the changes to the shape of the vertebrae are severe enough to impinge on the spinal cord. [3]

Risk Factors

Roach back is a rare condition in horses with no specific age or gender-based risk factors. This condition is thought to be more prevalent in Thoroughbreds, particularly those with pre-existing leg joint flexion issues. [1][4]

Horses with conformation faults that directly impact their posture may be at higher risk of developing roach back. Compensation following an injury may also lead to development of acquired roach back, which underscores the importance of following an individualized rehabilitation program after injury.

Diagnosis

Diagnosis of roach back is based on a thorough physical examination, with particular focus on the horse’s stance, posture, and behavior. [1] The veterinarian may also perform a basic neurological assessment to rule out any underlying nerve or brain issues. [1]

After assessing the horse at the trot and canter, the veterinarian may also want to see how the horse moves under saddle. [1]

Depending on severity and the presence of other symptoms, additional diagnostics may be recommended. Tools that may be used to confirm roach back, potential underlying causes in the case of acquired roach back, and secondary problems related to roach back include: [1][3]

  • Radiography (X-rays)
  • Scintigraphy (bone scan)
  • Myelography
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Treatment & Prognosis

Since kyphosis in horses is a structural deformity of the spine, there is no definitive cure for the condition. Treatment is tailored to the severity of the condition.

For horses where roach back is merely a cosmetic concern, the only “treatment” required may be appropriate saddle fitting and monitoring for signs of pain under saddle.

For horses with signs of pain, common strategies include:

The prognosis for horses with mild or moderate cases of roach back is good. They may even continue to be ridden and participate in athletic activities. The prognosis for horses with severe roach back, especially where there are neurological or musculoskeletal issues, is more guarded and a return to performance may not be feasible.

For severe cases related to injury, such as spinal fracture, humane euthanasia may be the only option. [8]

Prevention

Since the exact mechanism behind the development of congenital roach back is not fully understood, there are no specific prevention strategies available. However, it’s always recommended to follow best practices to ensure overall broodmare health to maximize the chance of producing a healthy foal.

Strategies to support broodmares during pregnancy include:

  • Nutrition & Management: Ensure the mare’s diet is carefully adjusted to meet the specific nutritional demands of each stage of pregnancy. For detailed feeding guidance, visit our How to Feed a Pregnant Mare page and learn more about gestation and nutrient requirements.
  • Veterinary Care: Schedule regular veterinary check-ups to monitor the mare’s health and the progress of the pregnancy, ensuring any issues are identified and addressed promptly.
  • Preventative Health Practices: Adhere to recommended vaccination and deworming protocols to protect both the mare and her developing foal. For detailed schedules and guidelines, check out our
    Vaccination Guide for Horses and Deworming Your Horse resources.

Additionally, your veterinarian may advise against breeding mares that have previously produced a foal with roach back, as this condition may have a genetic component.

Avoiding Injuries

Preventing cases of acquired kyphosis in horses may be possible by avoiding injury and following a well-structured training program. Key strategies to prevent back injuries include:

  • Work within your horse’s abilities
  • Train on appropriate footing
  • Allow sufficient recovery between training sessions
  • Spend time warming up and cooling down before and after exercise
  • Ensure tack is well-fit and in good working condition
  • Provide a well-balanced diet that meets all of your horse’s energy and nutritional requirements

Finally, if your horse is recovering from an injury, you can help prevent acquired roach back by addressing compensatory movements. Work with your veterinarian to develop an individual rehabilitation and return-to-work plan so your horse can make a full recovery without secondary complications.

Frequently Asked Questions

Here are some frequently asked questions about roach back in horses:

Summary

Roach back, also known as kyphosis or kyphoscoliosis, is a rare conformation defect in the horse’s back that leads to an abnormal curvature of the spine.

  • Congenital roach back is related to issues during the development while the horse is in utero. Acquired roach back is usually secondary to injury or other musculoskeletal issues
  • The characteristic symptom is an abnormal topline that is either flat or convex. In severe cases, pain, poor mobility and neurological deficits may also be present
  • Treatments aim to reduce pain and retain mobility and include pain management, physical therapy, and proper saddle fit
  • In most cases, horses with roach back can live a long and healthy life, and continue ridden work as long as tack is appropriately fitted
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References

  1. Cauin. E., Assessment of Back Pain in Horses. In Practice. 1997.
  2. Ghasemi. S. et al., Congenital Kyphoscoliosis Associated with Thoracic Hemivertebrae in a 9‐month‐old Racking Filly. Equine Veterinary Education. 2023.
  3. De Heer. N. and Nout. Y. S., Congenital Kyphosis Secondary to Lumbar Vertebral Hypoplasia Causing Paraparesis in a Friesian Foal: Congenital Kyphosis in a Friesian Foal. Equine Veterinary Education. 2011.
  4. Baxter. G. M., Ed., Adams and Stashak’s Lameness in Horses. Seventh edition. Wiley-Blackwell, Hoboken, NJ. 2020.
  5. Jeffcott. L. B., Disorders of the Thoracolumbar Spine of the Horse — a Survey of 443 Cases. Equine Veterinary Journal. 1980. View Summary
  6. Ony. E. E., A Closer Look at the Equine Spine. Kentucky Equine Research. 2014.
  7. Wong. D. M. et al., Hindlimb Paresis Associated with Kyphosis, Hemivertebrae and Multiple Thoracic Vertebral Malformations in a Quarter Horse Gelding. Equine Veterinary Education. 2010.
  8. Kothstein. T. et al., Radiographic Diagnosis: Thoracic Spinal Fracture Resulting in Kyphosis in a Horse. Veterinary Radiology & Ultrasound. 2000.