Use of thoracic ultrasound to investigate respiratory disease

Ultrasound of the thorax has been used for several decades to investigate suspected respiratory disease in foals and adult horses. Unlike radiography (especially of adult horses), ultrasound can be performed in both an ambulatory and hospital setting. Initial screening can typically be performed with equipment readily available to most equine practitioners, with follow-up more advanced imaging performed using more specialised equipment as required. In horses with suspected intrathoracic disease, ultrasound can be used to identify pleural effusion, pneumothorax, rib fractures, pulmonary parenchymal disease, diaphragmatic hernias and other miscellaneous conditions.

Ultrasound examination is indicated in the investigation of suspected respiratory disease in foals and horses. Clinical findings that might prompt ultrasound investigation include dull lung sounds ventrally (suggestive of pleural effusion), dull lung sounds dorsally (suggestive of pneumothorax) and fever, and so-called ‘large airway’ sounds (suggestive of pneumonia). In horses and foals with suspected thoracic trauma, ultrasound can be very useful to identify fractured ribs and haemothorax or pneumothorax.