Equine Health Update EHU Vol 20 Issue 03 - Page 36

EQUINE | CPD Article very important 12 to identify areas of possible lung involvement and in particular to locate dull ventral areas with loud radiating cardiac sounds 3 which would indicate effusion6 . Pleural friction rubs indicating pleural inflammation 11 are often heard at the end of inspiration and beginning of expiration before an increase of pleural effusion volume reduces all sounds heard 3 . A re-breathing bag to detect abnormal lung sounds, although useful in suspected early acute presentations, may cause additional dyspnea and should be used cautiously 13 . A lack of lung sounds in the ventral region and a painful response to chest percussion with a dull resonance indicates the presence of pleural effusion 11 . The most practical diagnostic test is thoracic ultrasonography 12 15 to confirm the presence of pleural effusion and assess fluid volume 15 This can be easily performed patient- side in the stable, thereby allowing a rapid definitive diagnosis to be made 17 and aids the client in making an informed treatment decision. Thoracic ultrasonography may be performed preferably with a 3.5 – 5 MHz sector scanner or linear probe and the following is assessed 3 15 : 1. Free fluid within the thorax – approximate volume and appearance – loculated / hypoechoic / anechoic 2. Pleural thickening 3. Pulmonary consolidation 4. Fibrinous adhesions 5. Fluid within airways 6. Lung field – lungs can be displaced dorsally and axially due to large effusions 7. Free gas Ultrasound images showing a pleural effusion 36 • Equine Health Update •