Thoracic percussion to determine the caudal lung border in healthy horses

BACKGROUND: The application of equine thoracic percussion has been ignored because of the availability of modern imaging techniques. Ultrasonography is a reliable tool in determining the caudal lung border of horses. The aim of the study was to compare percussion with ultrasonography to determine lung borders in horses. HYPOTHESIS: That thoracic percussion can detect the caudal lung border and that its accuracy is comparable with thoracic ultrasonography. ANIMALS: Fifteen randomly chosen, healthy, Warmblood horses. METHODS: The caudal lung border was detected by percussion and ultrasonography at the end of inspiration and expiration on both sides of the thorax. A reference point close to the withers was determined, allowing standardized measurements. The distance between this point and the caudal lung border in different intercostal spaces (ICS) was measured by a tape measure. RESULTS: No significant difference was found between percussional and ultrasonographic results. Greater differences were found between inspiration and expiration by ultrasonography compared with percussion in all intercostal spaces on both sides of the thorax. It was significant (P = .028) in the 12th ICS in the right hemithorax. CONCLUSIONS AND CLINICAL IMPORTANCE: Percussion is a reliable tool to determine the caudal lung border in healthy horses. Differences caused by the displacement of the lung during respiration should be taken into consideration when applying either method.