Carpometacarpal osteoarthritis in thirty-three horses.

This research examines the characteristics, clinical symptoms, and radiographic changes associated with Carpometacarpal Osteoarthritis (CMC-OA) in horses, and assesses the long-term outcome of this condition. The study concludes that conventional treatment methods have been largely unsuccessful, with majority of the horses ultimately euthanized.

Objectives and Methodology

The primary objectives of this study were:

• To outline the signalment (demographic information of animals including breed, age, sex), clinical symptoms, and radiographic indicators associated with CMC-OA in horses.
• To assess the long-term outcomes of this condition.

The study was based on a review of medical records of 33 horses diagnosed with CMC-OA during the period from 1992 to 2007. Information collected from these records related to signalment, clinical findings, and radiographic changes. Further data was obtained by contacting owners for update on the horses’ lameness progression, response to treatment, and overall outcome.

Findings

The significant findings from the study were:

• CMC-OA was identified in 39 limbs and commonly found in middle-aged and older Quarter Horses and Arabians.
• Symptoms included severe lameness that hindered normal functioning, along with characteristic swelling located over the articulation between the 2nd metacarpal and 2nd carpal bones.
• Radiographic changes observed included new bone proliferation, narrowed joint spaces, and subchondral lysis (destruction of subchondral bone).
• Out of 20 horses that were followed up, 7 out of 14 treated horses were euthanized within 4 years and 4 out of 5 untreated horses within 3 years, indicating a severe impact of the condition.

Conclusion

Based on the study’s findings, the researchers concluded that:

• CMC-OA appears to primarily affect Quarter Horses and Arabians in the studied region.
• The response to conservative treatment for CMC-OA was typically poor and short-lived. Consequently, many horses had to be euthanized.
• Conventional treatment methods have so far been unsuccessful for treating horses with CMC-OA.