The macroscopical anatomy of the lungs and thorax of the African lion (Panthera leo)

The left and right lungs extend from the second rib to the 13th, while only a small portion is present cranial to the 4th rib. The basal border of the left lung extends horizontally from the second costochondral junction (CCJ) to just ventral to the seventh CCJ, and then dorso-caudally to the angle of the 13th rib. The right lung has a similar configuration except for the basal border, which is located above the fifth to the sixth CCJ. The cardiac incisure is more prominent in the right lung and is formed by the notched space between the ventral margins of the cranial and middle lobes. The lungs are well-lobated, with complete fissures laterally but none medially. The trachea and primary bronchi are large and have a wide, thin membranous part. The muscular front limbs could limit cranial thoracic expansion, with the result that the bulk of the functional lung capacity is present caudal to the tricipital line. Recommended sites for intracardiac injections are on either side of the fifth CCJ, and for thoracocentesis, just dorsal to the seventh or eighth CCJ. Care is needed while intubating a lion's trachea because of the delicate membranous part.