Osteochondrosis and copper: histology of articular cartilage from foals out of copper supplemented and non-supplemented dams.

This research examines whether copper supplementation in pregnant horses (dams) could affect the development of cartilage abnormalities in their offspring (foals). However, the results indicate there weren’t significant changes in the frequency of cartilage irregularities in the foals, whether their mothers received copper supplementation or not.

Research Methodology

• The research involved 22 Thoroughbred foals that were 160 days old. The foals came from either copper supplemented or non-supplemented dams.
• Mares that received copper supplementation were given calcium copper edetate injections in late gestation. The dosing schedule included injections at approximately 220, 248, 276, and 304 days of gestation, and then every two weeks until the mare gave birth.
• Articular cartilage from the foals was collected post-euthanasia from four defined sites that are typically susceptible to the development of osteochondrosis (OC), a disease affecting the growth and development of cartilage and bone.
• The collected cartilage samples were then studied for indications of early cartilage abnormalities and established dyschondroplastic (DCP) lesions, which are areas of abnormal cartilage growth.

Research Findings

• The study checked hostological appearance of chondrocytes (cells responsible for cartilage formation) using haematoxylin and eosin staining. Also, samples were stained with toluidine blue to determine the proteoglycans content (complex proteins responsible for the resilience and flexibility of the cartilage).
• The research found no significant variation in the frequency of cartilage irregularities or histological abnormalities between foals whose dams received copper supplementation and those that did not.
• Similarly, the copper concentration in the liver of the foals at birth and at 160 days of age showed no significant influence on cartilage abnormalities.
• Alkaline phosphatase (ALP) activity, an enzyme associated with bone and liver health, was consistent across all samples.
• The activity of cathepsin B, an enzyme involved in the degradation of cartilage, varied among different sample sites and appeared in chondrocyte clusters.

Conclusions

• The role of copper in the development, resolution, or progression of dyschondroplastic lesions is not clearly understood based on this study. However, the absence of a significant impact from copper supplementation on the frequency of cartilage abnormalities suggests copper may not have a strong influence in these areas.
• The study highlights the importance of continuing research into understanding the subclinical (not clinically visible) early stage of DCP lesions and the factors that influence the development or resolution of these lesions.