Cervical Vertebral Lesions in Equine Stenotic Myelopathy.

This study investigates skeletal lesions in certain cervical vertebrae of Thoroughbred horses with cervical stenotic myelopathy, comparing them with those from controls. It found that such horses displayed more frequent and severe hallmarks of this condition, including bone cysts, offering supporting evidence that abnormalities in development and biomechanical influences contribute to this form of Equine Myelopathy.

Comparative Study of Lesions

The researchers compared skeletal lesions in the cervical vertebrae (from C2 to C7) of Thoroughbred horses with cervical stenotic myelopathy to controls. There were a total of 17 males and 2 females in the diseased sample group, aged between 6 to 50 months. The control group consisted of 6 males and 3 females aged between 9 to 67 months. The research found that:

• Lesions were more frequently and severely observed in horses with cervical stenotic myelopathy.
• Lesions were not restricted to areas of spinal cord compression.

Use of Imaging and Characterisation of Lesions

Magnetic resonance imaging was employed to find the lesions, which involved both the articular cartilage and subchondral bone. These were further characterized using micro-computed tomography and histopathology, revealing that:

• The most common histologic lesions included osteochondrosis, osseous cyst-like structures, fibrous tissue replacement of trabecular bone, retained cartilage matrix spicules, and osteosclerosis.
• Osseous cyst-like structures were interpreted as bone cysts as they were enclosed cavities with a cellular lining separating them from the surrounding bone. This discovery is reported to be the first of its kind.

Pathogenesis of Equine Cervical Stenotic Myelopathy

The study’s findings support previously hypothesized causes of the disease, affirming that:

• Developmental abnormalities likely contribute to equine cervical stenotic myelopathy.
• Secondary biomechanical influences on the cervical spine may also be a contributing factor.

This study provides new insights into the skeletal problems of horses with cervical stenotic myelopathy and paves the way for future research into the development of possible treatments and preventive measures.