Osteochondrosis and copper: histology of articular cartilage from foals out of copper supplemented and non-supplemented dams.
Authors: Gee E, Davies M, Firth E, Jeffcott L, Fennessy P, Mogg T
Journal: Veterinary journal (London, England : 1997)
Summary
# Editorial Summary Late-gestation copper supplementation of mares has been proposed as a preventative measure against osteochondrosis in foals, but Gee and colleagues found no histological evidence supporting this protective effect. Their study examined articular cartilage from 22 Thoroughbred foals at 160 days of age, harvested from four anatomical sites predisposed to osteochondrotic lesions, using haematoxylin and eosin staining alongside toluidine blue staining for proteoglycan assessment and histochemical detection of alkaline phosphatase and cathepsin B activity. Regardless of whether mares had received four injections of calcium copper edetate (250 mg each) during late gestation or the foals' hepatic copper concentrations at birth or 160 days, no statistically significant differences emerged in the frequency of cartilage irregularities or histological abnormalities between treatment groups. Notably, minor histological abnormalities including chondrocyte clustering and cathepsin B expression (which varied by site) were observed even in clinically normal animals, suggesting these may represent early dyschondroplastic lesions with uncertain clinical significance and resolution potential. These findings suggest that whilst copper's role in cartilage maturation remains unclear, maternal copper supplementation as currently administered may not meaningfully modify the histological landscape of developing articular cartilage, warranting reconsideration of supplementation protocols and highlighting the need for further investigation into copper's influence on lesion progression or resolution.
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Practical Takeaways
- •Maternal copper supplementation via injection in late gestation does not appear to prevent early cartilage abnormalities detectable at 160 days of age, questioning the protective effect previously suggested
- •Routine Cu supplementation of pregnant mares may not be justified as a strategy to prevent osteochondrosis development in foals based on current evidence
- •Minor histological changes in cartilage from clinically normal foals may represent dynamic processes; further longitudinal studies are needed to determine which lesions resolve spontaneously versus progress to clinical disease
Key Findings
- •Cu supplementation of dams during late gestation had no statistically significant effect on cartilage irregularities or histological abnormalities in foals at 160 days of age
- •Foal liver Cu concentration at birth or 160 days of age showed no significant correlation with cartilage abnormalities at predisposed sites
- •Minor histological cartilage abnormalities were observed in clinically normal foals, suggesting early dyschondroplastic lesions that may resolve or progress
- •Cathepsin B expression varied between cartilage sites and was localized to chondrocyte clusters, while ALP expression remained similar across all samples