- Cervical (neck) osteoarthritis is a potential source of pain and poor performance in sport horses
- Researchers examined cervical x-rays for 104 jumping horses during the 2018 winter circuit in California
- A majority of horses did have some radiographic evidence of osteoarthritis in the cervical spine region
- Horses that had jumped at a higher height had more advanced osteoarthritis at the C6-C7 joint
Osteoarthritis frequently occurs in sport horses and can cause pain, stiffness, poor performance and lameness. However, the prevalence of this condition in the necks of jumping performance horses was unknown.
An international group of researchers, funded by the Sport Horse Research Foundation, sought to better understand the prevalence of cervical osteoarthritis in jumping horses competing in California.
Cervical osteoarthritis occurs when the cartilage between the vertebrae in a horse’s neck breaks down, resulting in joint inflammation and bone reaction on the opposing joint surfaces (Figure 1) and can cause neck pain, stiffness, poor performance, and lameness, among other issues. Many factors can predispose a joint to developing osteoarthritis, such as a horse’s age, trauma to the joint, suboptimal biomechanics, and obesity.
Osteoarthritis is commonly observed in sport horses, and it is hypothesized that the large range of motion that the horse’s neck goes through during the takeoff and landing contributes to the occurrence of this disease in jumping horses. More information is needed about the prevalence of osteoarthritis in the neck of jumping horses to better understand what factors predispose a horse to developing this condition.
To shine a light on these issues, scientists and veterinarians teamed up to assess the cervical x-rays of 104 warmblood jumpers (34 mares, 58 geldings, 12 stallions) that were competing at the HITS Coachella Desert Circuit in 2018. Horses included in this study were all clinically sound and passed a neurological exam, were competing at heights of 1.0 m–1.6 m, and were between the ages of 6–18 years. During the initial assessment, 34 (33%) of these horses were considered to have neck pain during palpation and 40 (38%) horses had some restriction to their neck mobility.
The researchers discovered that most horses had some level of osteoarthritis in their cervical spine region (see Figure 2). Osteoarthritis became more common moving down the neck, with only 15.3% of horses having some osteoarthritis at C3-C4 as compared to 67.3% displaying osteoarthritis at C6-C7.
Interestingly, horses that had competed at a higher level tended to have a greater prevalence of osteoarthritis in the cervical spine at C6-C7 as compared to horses that had competed at lower heights throughout their careers. The authors hypothesized that, due to the anatomy of the cervical spine, where the C5, C6, and C7 vertebrae are more upright to facilitate neck flexion and extension, the increased range of motion these joints go through while jumping likely places significant mechanical loads on these areas that could lead to cartilage degeneration.
Surprisingly, the authors found no relationship between the presence of osteoarthritis on x-rays and the horse’s age, the horse’s age when it started jumping, neck pain, or neck range of motion.
Given the relatively high prevalence of osteoarthritis the researchers observed in the neck of jumping horses, it is possible that mild osteoarthritis in the C5-C6 and C6-C7 areas of the neck may be of low clinical significance and not necessarily indicative of pain or poor performance.
Taken together, findings from this study highlight that degenerative changes to the cervical spine commonly occur in jumping horses. Future research is needed i) to better understand the mechanism causing these changes, ii) to determine if certain disciplines predispose a horse to cervical osteoarthritis, iii) to follow the natural history of cervical osteoarthritis, and iv) to develop preventative strategies.
This study was funded by the Sport Horse Research Foundation (SHRF). The SHRF seeks to advance and direct scientific research and education to enhance the health, athletic potential, and career longevity of sport horses. Contributions donated to the SHRF are fully tax-deductible and funds are used to support cutting-edge and impactful scientific studies.