Objective: To describe the ultrasonographic appearance of the lungs, pleura, and mediastinum of cattle.
Design: Transcutaneous ultrasonography of the lungs and pleura was performed on the right and left sides of the thorax. The mediastinum was examined transesophageally.
Animals: 50 healthy cows.
Procedure: The thoracic wall, pleura, and pulmonary surface were visualized on both sides of the thorax via transcutaneous ultrasonography. The cranial mediastinal lymph node, right azygos vein, aorta, and caudal vena cava were visualized via transesophageal ultrasonography.
Results: The layers of the thoracic wall appeared as narrow bends that varied in echogenicity. They were followed medially by an echogenic line that represented the costal and pulmonary pleurae. Reverberation artifacts were seen medial to the pleura. The pulmonary parenchyma could not be visualized ultrasonographically because of its air content. The cranial mediastinal lymph node appeared circular to oval. The right azygos vein was situated immediately adjacent to the cranial mediastinal lymph node. The aorta appeared circular to oval on cross-sectional view with an echogenic wall and an anechoic lumen. The caudal vena cava appeared as a tubular structure with an anechoic content and an echogenic wall.
Conclusion: Ultrasonography of the lungs, pleura, and mediastinum in healthy cows provides information that can be used as a reference when examining cattle with suspected disease of the thorax.