Early changes in biomarkers of skeletal metabolism and their association to the occurrence of osteochondrosis (OC) in the horse.

This research attempts to identify early indicators for the development of Osteochondrosis (OC), a bone and cartilage condition in horses, by studying various biomarkers related to bone and cartilage metabolism. It found a significant link between the condition and certain biomarkers, particularly osteocalcin, in the early stages of a foal’s life.

Study Design and Methodology

• The research involved two groups of foals with different feeding levels – a high level (20 foals) and a moderate level (19 foals), from birth to one year of age. The researchers closely monitored each foal’s bodyweight, withers height, and cannon width.
• They assessed the osteoarticular status of all the foals through radiography at 5.5 months and 11 months, and through necropsy for 8 foals from each group at 12 months.
• Levels of various biomarkers reflecting changes in bone and cartilage turnover, such as osteocalcin, CTX-1, CPII, and C2C, in the foals’ serum were measured at eight different time intervals – from 2 weeks to 52 weeks of age.
• Foals’ serum ratios between biomarkers of tissue formation and degradation were calculated at every stage.

Findings of the Study

• Age-related patterns were identified in the concentration levels of biomarkers in serum, demonstrating a notably higher metabolic activity prior to 20 weeks of age.
• The biomarkers’ concentration levels were not influenced by the feeding level.
• Bodyweight showed a negative correlation with C2C and CTX-1 levels, while withers height had a positive correlation with osteocalcin levels, osteocalcin/CTX-1 ratios, and CPII/ C2C ratios.
• Osteocalcin concentration at 2 weeks and CPII/ C2C ratio at 20 weeks correlated strongly with the occurrence of OC, as diagnosed through radiography at 5.5 months.
• Similar strong correlation was observed between osteocalcin levels and OC diagnosed through radiography at 11 months, yet no significant association was found between CPII/C2C ratio and OC at that time.

Conclusions and Implications

• The study highlights the significant connection between the onset of OC lesions and anabolic changes in bone metabolism during the initial weeks post birth, primarily evidenced by the strong relation with osteocalcin levels.
• This suggests that measuring osteocalcin concentrations in the initial weeks after birth could be an effective method for predicting the risk of OC development. This finding has potential value for early diagnosis and intervention for horses susceptible to OC.