EVALUATION OF SUPERFICIAL DIGITAL FLEXOR TENDINITIS IN RACING HORSES THROUGH GRAY-SCALE HISTOGRAM ANALYSIS OF TENDON ULTRASONOGRAMS

Normal and diseased superficial digital flexor tendons at different st ages of healing from seven Thoroughbred horses, aged 3-6 years, were e valuated by correlation of gray scale histogram analysis of tendon cro ss-sectional ultrasonograms with histopathologic examination. Normal t endon and tendons at different stages of healing, excluding acute tear stage, were characterized by normally distributed histogram patterns. The histogram mean value of normal tendons was higher than the corres ponding values in diseased tendons at different stages of healing (p < 0.01). In addition, the histogram mean of acute lesions was lower tha n for early fibrosis or healed lesions (p < 0.01). The histogram mean increased as healing progressed. The results show that gray scale hist ogram analysis of tendon ultrasonogram can be used to distinguish betw een normal and abnormal superficial digital flexor tendon in racing ho rses.