Osteochondrosis (Osteochondritis Dissecans) in Lusitano Horses: Prevalence and Characteristics.
Authors: Ramos Sofia, Pinto António, Crespo João, Marques João Paulo, Bettencourt Elisa, Gama L T, Monteiro Susana
Journal: Journal of equine veterinary science
Summary
# Osteochondrosis in Lusitano Horses: Prevalence and Key Characteristics Osteochondrosis (OC/OCD) remains a significant developmental orthopaedic disease affecting performance horses, yet its occurrence in Lusitano breeding stock has not been systematically documented until now. Researchers examined radiographs from 302 Lusitano horses aged 1–12 years, assessing the metacarpometatarsophalangeal, tarsocrural and femoropatellar joints using a standardised five-point scoring system to establish prevalence and phenotypic patterns. Radiographical evidence of OC(D) was identified in 53.3% of the cohort, with the distal intermediate ridge of the tibia being the most commonly affected site (31.0% of all lesions); notably, mild lesions (scores 1–2, representing flattening) predominated at 36.8%, whilst only 16.6% of horses showed advanced fragmentation (scores 3–4). The tarsocrural joint was most frequently involved overall, followed by metacarpophalangeal joints and lastly the femoropatellar joint, with a positive correlation observed between contralateral limb involvement. These findings—comparable to prevalence rates in Spanish Purebred horses but with a lower fragmentation rate—establish a crucial baseline for understanding OC(D) phenotypic expression in Lusitano breeding populations and provide essential data for future genetic studies aiming to identify heritable risk factors and inform selective breeding decisions.
Read the full abstract on PubMed
Practical Takeaways
- •Over half of Lusitano horses examined show radiographic evidence of OC(D); screening young animals (1-12 years) should be considered routine before purchase or training intensification
- •Tarsocrural joint involvement predominates in this breed—focus radiographic examination here first and be alert for bilateral lesions, as contralateral joints show positive correlation
- •While prevalence matches Spanish Purebred horses, Lusitanos show less fragmentation, suggesting potentially better long-term prognosis and less need for surgical intervention in many cases
Key Findings
- •Prevalence of osteochondrosis in Lusitano horses is 53.3%, with most lesions being scores 1-2 (36.8%)
- •Distal intermediate ridge of the tibia in tarsocrural joints is the most affected site (31.0% of assessed joints)
- •Tarsocrural joints are most commonly affected overall, followed by metacarpometatarsophalangeal and femoropatellar joints
- •Only 16.6% of horses showed fragmentation (scores 3-4), suggesting lower severity in Lusitanos compared to Spanish Purebred horses