Feline Thorax

The overall shape of the feline thorax is narrower ventrodorsally and more elongated compared with the dog, giving the feline thorax a more triangular appearance. Cranially, the thorax extends to the level of the thoracic inlet at the level of the manubrium ventrally, first ribs laterally, and cervicothoracic spinal junction dorsally. The pleural space is a potential space located between the parietal and visceral pleura, and is not visualized on normal thoracic radiographs. The pulmonary parenchyma consists of alveoli, interstitial tissue, bronchial walls, and pulmonary vasculature. The mediastinum is a true open space between the right and left pleural cavities. The mediastinum can be divided into cranial, middle, and caudal portions. Rib fractures are a common cause of extrathoracic abnormalities. Pleural space abnormalities include pleural effusion and pneumothorax. A true generalized decrease in lung opacity in the cat is secondary to either hypovolemia or hyperinflation.