Small Animal Radiology and Ultrasound: A Diagnostic Atlas and Text

Chapter Two The Thorax 195
A
Fig. 2-175 A and B, A 6-month-old male German Shepherd dog with a history of respiratory distress.
An alveolar pattern infiltrate typified by poorly defined and coalescent densities is present in
the dorsal portions of the caudal lung lobes. A few air bronchogram signs are present. The hilar
region is less severely involved. The radiographic findings are suggestive of a noncardiogenic pulmonary
edema. Diagnosis: Noncardiogenic pulmonary edema secondary to electric shock. The owners
discovered that the dog had been chewing on an electric lamp cord.
B
squamous cell carcinoma of the bronchus, which usually results in partial or complete
atelectasis of the affected lung lobe or lobes. 545 Alveolar cell carcinoma usually appears as
multiple, poorly defined foci of alveolar pattern infiltrates in one or more lobes. This also
may be associated with a fine linear interstitial infiltrate. Bronchoalveolar carcinoma frequently
manifests as a large, focal area or areas of alveolar pattern infiltrate, with multiple
smaller areas of infiltrate or nodule formation in other lobes. Lymphosarcoma rarely may
produce a focal or multifocal alveolar infiltrate.
P U L M O N A RY H E M O R R H AG E O R C O N T U S I O N
Pulmonary hemorrhage or contusion may result from chest trauma or coagulopathy.
77,157,159 Rib fractures may or may not be present; however, the presence of recent
rib fractures or a history of recent trauma strongly suggests that the density is a contusion.
Any lung lobe or portion of a lobe may be involved. Pneumothorax, pneumomediastinum,
hydrothorax, and diaphragmatic hernia can be seen concomitantly with
lung contusion. Uneven lung lobe density in conjunction with bilateral pneumothorax
or hydrothorax or both suggests that a pulmonary infiltrate is present in the lobe that
is most dense and, in the presence of trauma, this is likely to be a pulmonary contusion.
P U L M O N A RY E M B O L I C D I S E A S E
Pulmonary embolic disease may occur in conjunction with dirofilariasis (Fig. 2-176),
hyperadrenocorticism, glomerulonephritis, coagulopathies, and other clinical syndromes.
148,546-553 Survey radiography is relatively insensitive in the detection of this problem.
Pulmonary scintigraphy or angiography is more likely to confirm the diagnosis. 70
Radiographically, pulmonary emboli occasionally may produce a decreased pulmonary