Pathologic changes in the lumbosacral vertebrae and pelvis in Thoroughbred racehorses.

This research looks into the prevalence, characteristics, and severity of soft-tissue and bone lesions in the lower back and pelvic region of Thoroughbred racehorses. The study reveals the high occurrence of degenerative changes impacting vertebral processes, intervertebral articulations, and sacroiliac joints in these racehorses, which could contribute to poor performance and lameness in competitive horses.

Study Objectives and Methods

• The study aimed to understand the frequency, characteristics, and severity of soft-tissue and bone lesions in the lower thoracic and lumbosacral vertebral columns and the pelvis area of Thoroughbred racehorses. These horses were either fallen or euthanatized at California racetracks from October 1993 to July 1994.
• Lumbosacral and pelvic specimens were obtained and visually inspected for soft-tissue and bone lesions. This was done to assess any pathological changes that could impact the racehorses’ performance.

Research Findings

• The examination revealed acute sacroiliac joint injury in two specimens. However, no signs of chronic laxity or subluxation of the sacroiliac joint were found in any of the samples.
• It was observed that 92% of the specimens had impingement of the dorsal spinous processes, and 97% had impingement of the transverse processes. Degenerative change in thoracolumbar articular processes was identified in 97% of the specimens, indicating a high occurrence of degenerative conditions.
• Furthermore, all specimens showed evidence of degenerative changes at the lumbar intertransverse joints and sacroiliac articulations. In some cases, the degenerative changes were found to be widespread and severe.

Implications and Conclusions

• The study reveals the high prevalence of various degenerative changes affecting the vertebral processes, intervertebral joints, and sacroiliac joints in Thoroughbred racehorses.
• Several types of vertebral and pelvic lesions need to be considered when evaluating the back and pelvis of horses clinically. These undiagnosed vertebral or pelvic lesions could be an essential contributor to inadequate performance and lameness in athletic horses.
• Thus, more attention needs to be paid to these possible lesions during the medical examination to enhance the performance, lifespan, and wellbeing of Thoroughbred racehorses.