It is well known in human medicine as a complication of chest injury and emphysema. It the case of our dolphin baby, it was the cause of the rush of air we observed on opening the chest. In addition to the pneumothorax a great deal of blood was lost into the chest from the torn lung. This could have been fatal by itself. It is easy to explain the cause of death in this animal.
External features indicate the dolphin was a couple of days old.
The presence of milk in the stomach and in the intestine indicates that the baby was able to nurse at least once, perhaps several times. Histologic examination of the torn lung showed no healing reaction whatever. The injury was so massive and the results so severe that survival could have not have been more than an hour from the incident, at most. These facts all speak strongly against any sort of birth trauma. It is hard to imagine how there could have been such an injury to the lung without some external evidence of trauma.