Natural progression of tarsal osteochondrosis in Standardbred pacers and trotters.
Authors: McCoy Annette M, Lopp-Schurter Christine T, Bishop Rebecca C, Narotsky Amy, Grogger Kyle, Kemper Ann M
Journal: Veterinary surgery : VS
Summary
# Editorial Summary: Natural Progression of Tarsal Osteochondrosis in Standardbred Foals McCoy and colleagues tracked 148 Standardbred foals with radiographic examinations every two months from two to twelve months of age, combining imaging data with video analysis of their natural movement patterns to investigate whether tarsal osteochondrosis (OC) lesions heal spontaneously and whether gait preference influences this outcome. Nearly 70% of foals displayed OC lesions at two months, yet the vast majority resolved naturally—only 22% retained lesions by one year, with 84.5% of healing cases occurring by six months of age, though 28 horses progressed to osteochondrosis dissecans (OCD). Surprisingly, gait preference showed no association with lesion presence, healing trajectory, or OCD development, despite the inherent biomechanical differences between pacing and trotting; notably, foals spent less than 1% of observed time engaged in either gait. These findings establish that the critical therapeutic window for tarsal OC occurs within the first six months of life and suggest that early lesion detection and management during this period warrant investigation into modifiable risk factors (nutritional, conformational, or genetic) rather than gait-based interventions. For practitioners, this work implies that initial OC findings in young Standardbreds should prompt close monitoring during the first half-year of life, when most resolution occurs, while recognising that natural healing is the probable outcome for the majority of lesions.
Read the full abstract on PubMed
Practical Takeaways
- •Tarsal OC is highly prevalent in young Standardbreds but most lesions self-resolve early—don't panic at 2-month radiographs but monitor closely through 6 months of age
- •Focus preventative and management strategies on the first 6 months of life, as this is the critical window for lesion healing or progression to OCD
- •Training gait (pace vs trot) does not explain OC development in this breed, suggesting genetic or nutritional factors warrant investigation instead
Key Findings
- •69.6% of Standardbred foals had tarsal OC lesions at 2 months of age, declining to 21.6% by 12 months
- •84.5% of healing lesions resolved by 6 months of age, representing the critical healing window
- •28 horses (18.9% of those with OC) progressed to osteochondrosis dissecans
- •Gait preference (pacing vs trotting) was not associated with OC lesion presence or healing, despite foals spending <1% of time in these gaits