Table 3.

Differential diagnoses for specific radiographic patterns

Lobar Alveolar Consolidation	Focal Alveolar Consolidation
Aspiration pneumonia (cranioventral, right middle) Lung lobe torsion (cranial) Atelectasis secondary to mucus plugging (right middle most commonly)	Airway foreign body Primary pulmonary neoplasia (caudal) Metastatic neoplasia Noncardiogenic pulmonary edema

Diffuse Alveolar Pattern	Diffuse or Focal Interstitial Pattern
Acute respiratory distress syndrome Congestive heart failure (perihilar in dogs) Fluid overload Eosinophilic bronchopneumopathy Coagulopathy Metastatic neoplasia	Early bacterial pneumonia Imminent congestive heart failure Pneumocystis carinii infection Inhalant toxicity (eg, paraquat) Viral pneumonia