Severe carpometacarpal osteoarthritis in older Arabian horses.

The article details a study on a severe form of carpometacarpal osteoarthritis (CMC-OA) common in older Arabian horses. It explores the occurrence of osteoproliferative reactions, the potential impact of trauma, and the variations and absence of articulations between certain metacarpal bones in these horses.

Research Methodology

• The research is based on a retrospective study involving 31 horses diagnosed with severe CMC-OA.
• The team reviewed 405 sets of carpal radiographs from 3 hospitals to identify horses that displayed a significant osteoproliferative reaction in their CMC joint. An osteoproliferative reaction is characterized by the excessive formation of new bone in the joint.
• Owners of the horses were interviewed to gather an exhaustive history and current updates on each horse’s health.
• Specimens from necropsies (animal autopsies) from two hospitals were scrutinized to study the prevalence of two different types of articulations (joint connections) between the proximal second and third metacarpal bones in the horse’s body.

Findings and Inferences

• The evaluation discovered that out of the 31 horses identified with excessive osteoproliferative reaction in the CMC joint, 23 (74%) were Arabian horses.
• The average age of these affected Arabian horses was 14.4 years at admission, and 34.8% of these had a history of trauma.
• The majority of the surveyed Arabian horses were unable to be ridden due to the condition, and ten of these had to be euthanized due to extreme lameness.
• The study of the dorsal and palmar articulations between the second and third metacarpal bones in 177 horses revealed that the palmar articulation was absent in 48% of the Arabian horses. This absence was also found in 12.5% of non-Arabian horses in one hospital, including four horses that had CMC-OA.
• In another center, the palmar articulation was present in all eight surveyed Arabian horses but was missing in 24% of the non-Arabian horses.

Conclusions

• The study concludes that there is a high occurrence of the severe form of CMC-OA in Arabian horses, which may be a reflection of either regional prevalence or an absent palmar articulation between the second and third metacarpal bones.
• The researchers also suggest that some Arabian horses may develop severe CMC-OA as a direct consequence of carpal trauma.