The mediastinum and hemothorax, pyothorax, and pneumothorax in the dog.

Contrary to the reported clinical, anatomic, and histologic evidence of communication between the 2 pleural cavities through the mediastinum in the dog, it was found that acute or chronic pathologic processes in one pleural cavity remained confined to that cavity unless the mediastinum was mechanically injured. These results were obtained in a series of experiments involving 39 dogs in which hemothorax or pyothorax or pneumothorax was unintentionally induced.