🔍 Key Findings

• TGMO was common despite absence of overt lameness, with 18/34 dogs showing abnormal clinical examination findings.
• Ultrasonographic abnormalities were highly prevalent, with only 5/34 dogs classified as bilaterally normal and 29/34 showing mild or moderate lesions.
• Only four dogs had normal clinical, radiographic, and ultrasonographic findings, supporting a high prevalence of subclinical pathology.
• Pain on palpation over the fabella was considered the most clinically meaningful indicator of TGMO, whereas imaging abnormalities alone did not reliably indicate clinical disease.
• Gait analysis was sensitive but nonspecific, with asymmetry detected in 17 dogs, including some with otherwise normal findings.
• Radiographic mineralization or enthesiophytes were identified in 7/34 dogs (~20%), indicating chronic tendon pathology but not necessarily clinical symptoms.
• Moderate ultrasonographic lesions were present in 10 dogs, often associated with irregular supracondylar bone contours and occasionally pain or gait abnormalities.
• TGMO appears substantially underrecognized in agility Border Collies, supporting routine clinical and imaging assessment when hindlimb performance issues occur.