Today’s case is a 1-year-old female neutered Rat Terrier with a 10-day history of coughing, lethargy, inappetence, and diarrhea with melena. Fever of 104°F on physical exam. What are your findings?
Thorax: There is a soft tissue opacity mass present in the left caudal lung lobe. The mass is deforming the border between the caudal subsegment of the left cranial lung lobe and left caudal lung lobe on the right lateral projection, confirming its location in the left caudal lobe. There is increased opacity in the pleural space with visible fissure lines indicating a small pleural effusion. The cardiovascular structures are normal in size and shape. The musculoskeletal structures and portion of the abdomen included are normal.
Differential diagnoses for the left caudal lung lobe mass are most likely abscess or granuloma, possibly from an inhaled foreign body, given the fever and young age of the dog as well as the location of the mass. The pleural effusion is most likely inflammatory.
On recheck radiographs over the next month with antibiotics, the fever resolved but the mass persisted. A CT and lung lobectomy were performed, and the lung lobe was removed. Histopathology confirmed an abscess but did not identify a foreign body.