Thermography: a technique for subclinical diagnosis of osteoarthritis.

This study used thermography to identify subclinical osteoarthritis in racehorses, revealing that abnormal thermal patterns were able to detect early inflammatory changes indicative of osteoarthritis, even when not detectable through traditional radiographic methods.

Study Overview

• The study aimed at evaluating the potential of thermography to diagnose osteoarthritis in horses.
• Twenty Standardbred racehorses were examined at three consecutive 6-week intervals before and after exercise, with thermographic and radiographic evaluations carried out on the tarsus (hock) area.
• The horses were all from the same stable, cared for and trained under the same conditions.

Establishing Normal Patterns

• The researchers established normal thermographic patterns before and after exercise, corresponding to each horse’s underlying tarsal vasculature.
• A post-exercise warming trend was noticed and increases were uniform across healthy horses.

Detection of Abnormal Thermal Patterns

• The team observed abnormal thermal patterns that were localized and did not conform to the normal vascular distribution, suggesting a potential issue.
• Out of the 20 horses, only five were trained successfully and competed professionally, with one of these five revealing abnormal thermal changes.
• Four horses were deemed too slow for racing, all of who exhibited abnormal thermographic changes in their tarsi.
• Only one horse was clinically lame and showed both thermal increases and radiographic changes in the right tarsus.

Conclusions and Implications

• The researchers concluded that the slow racehorses likely experienced discomfort in their tarsi from early inflammatory changes, impairing their performance.
• These changes were not detectable using radiographic methods but were evident as abnormal thermal patterns on thermographic evaluation.
• Findings suggest that thermography could be a valuable tool in detecting early, subclinical signs of osteoarthritis in racehorses, potentially enabling a more proactive approach to treatment and enhancing race performance.