Genetic factors of equine osteochondrosis and fetlock osteochondral fragments: A scoping review - Part 2.
Authors: Van Mol B, Janssens S, Oosterlinck M, Pille F, Buys N
Journal: Veterinary journal (London, England : 1997)
Summary
# Editorial Summary Osteochondrosis and fetlock osteochondral fragments represent significant welfare and economic concerns in equine practice, with both environmental and genetic contributions to their development. Van Mol and colleagues conducted a comprehensive scoping review of 212 peer-reviewed studies to map the current evidence on genetic risk factors, identifying multiple quantitative trait loci and candidate genes associated with these osteochondral disorders. The review highlights substantial heritability variations depending on lesion type and location, yet reveals critical gaps: inconsistent phenotypic definitions across studies, small reference populations for genomic selection, and publication bias that skews our understanding of true disease prevalence. Key challenges limiting selective breeding programmes include the difficulty of accurate early phenotyping, insufficient standardisation in how lesions are characterised and recorded, and studbook policies that may not adequately support genetic improvement strategies. To advance preventive breeding and selection strategies, future research must employ uniform, precise phenotype definitions across larger, representative populations—a standardised approach that would substantially improve both animal welfare and economic outcomes for breeders and practitioners managing these costly conditions.
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Practical Takeaways
- •Genetic predisposition to osteochondrosis and fetlock fragments is documented but complex; breeding decisions should consider both genetic and environmental management factors rather than genetics alone
- •Current genomic testing limitations mean that precise, consistent clinical phenotyping and detailed lesion characterization at the individual level remains critical for effective management and breeding decisions
- •Collaboration across stud books and standardized recording of osteochondral lesions in breeding populations would enable faster progress in identifying and selecting against genetically susceptible animals
Key Findings
- •212 studies identified examining genetic and environmental risk factors for equine osteochondrosis and fetlock osteochondral fragments
- •Significant quantitative trait loci and candidate genes associated with osteochondral disorders have been identified but require further validation
- •Major challenges to genetic selection include inconsistent phenotype definitions, small reference populations, publication bias, and varying lesion-specific heritabilities across studies
- •Genomic selection shows considerable potential to reduce economic burden and improve animal welfare, but requires larger populations and standardized phenotyping protocols