Distinct histopathological features of pneumonia from different causes. A Bacterial pneumonia in porpoise PP140917. Neutrophils and fibrin fill an alveolar lumen. B Fungal pneumonia in porpoise PP121130. Fungal hyphae (arrowheads) with internal segments are present in cellular debris at the edge of a pulmonary abscess. C Parasitic pneumonia in porpoise PP040324. Nematode larvae (probably Stenurus minor) (arrowheads), macrophages, and eosinophils fill an alveolar lumen. Haematoxylin and eosin. Original magnifications: 40 X objective (A, C); 100 X objective (B).