Natural progression of tarsal osteochondrosis in Standardbred pacers and trotters.
Abstract: To determine the natural progression of tarsal osteochondrosis (OC) in a cohort of Standardbred foals and assess the impact of gait preference (trotting vs. pacing). Methods: Longitudinal observational cohort study. Methods: Client-owned Standardbred foals (n = 148). Methods: Tarsal radiographs were taken every 2 months from 2 to 12 months of age and foals were video monitored to document time spent pacing or trotting. Differences between groups were assessed using χ analysis. Survival analysis was used to determine if lesion healing differed between groups over time. Results: Of 148 horses, 103 (69.6%) had OC lesions at 2 months of age but only 32 (21.6%) still had OC lesions by 12 months. In 28 of these horses, the lesions had progressed to osteochondrosis dissecans (OCD). Of 71 horses with lesions that healed, 60 (84.5%) did so by 6 months of age. Gait was not associated with presence or absence of OC lesions or healing of lesions over time. Foals spent less than 1% of their observed time trotting or pacing. Conclusions: Tarsal OC lesions were prevalent in this cohort of young Standardbreds, and most lesions healed within the first few months of life. There was no evidence for direct biomechanical forces from movement at the pace or trot affecting the location of OCD fragment development. Conclusions: The critical window for tarsal OC lesion healing was prior to 6 months of age and further investigation of risk factors present during this time frame is warranted.
© 2026 The Author(s). Veterinary Surgery published by Wiley Periodicals LLC on behalf of American College of Veterinary Surgeons.
Publication Date: 2026-01-03 PubMed ID: 41482995DOI: 10.1111/vsu.70073Google Scholar: Lookup
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Cite This Article
APA
McCoy AM, Lopp-Schurter CT, Bishop RC, Narotsky A, Grogger K, Kemper AM.
(2026).
Natural progression of tarsal osteochondrosis in Standardbred pacers and trotters.
Vet Surg.
https://doi.org/10.1111/vsu.70073 Publication
Researcher Affiliations
- Department of Veterinary Clinical Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, USA.
- Department of Veterinary Clinical Sciences, Iowa State University, Ames, Iowa, USA.
- Department of Veterinary Clinical Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, USA.
- Hoosier Equine Veterinary Services, Anderson, Indiana, USA.
- Brazos Valley Equine Hospitals, Navasota, Texas, USA.
- Department of Veterinary Clinical Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, USA.
Grant Funding
- D16EQ-311 / Morris Animal Foundation
- D20EQ-046 / Morris Animal Foundation
- T35 OD011145 / ODCDC CDC HHS
- ILLU-888-349 / USDA Hatch Funds
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