The left mainstem bronchus appeared erythematous and inflamed, and the lumen was narrowed (Figure 3) during both phases of respiration but more so during expiration. The left cranial lobar and caudal segmental bronchi of
the left cranial lung lobe were visualized, as shown during inspiration (Figure 4) and expiration (Figure 5). The left cranial lobar and caudal segmental bronchi were erythematous and completely collapsed with expiration. The right
mainstem bronchus was examined next and appeared normal. However, evaluation of the right middle and accessory bronchi revealed
partial collapse during expiration (no gross evidence of inflammation was noted in these bronchi). Figures 6 and 7 show both the right caudal and accessory bronchi during inspiration and expiration, respectively.
Figure 5. The left cranial lobar and caudal segmental bronchi of the left cranial lung lobe during expiration. There is complete
collapse and moderate erythema of both bronchi.
Bronchoalveolar lavage was performed, and lavage samples from the bronchus of the left cranial lung lobe and the right mainstem
bronchus were collected and submitted for cytologic examination, bacterial culture, and antimicrobial sensitivity testing.
Figure 6. The right caudal (left side of image) and accessory bronchi during inspiration. No abnormalities are identified.
The dog recovered from anesthesia without complications, and treatment was started with intravenous fluids administered at
a maintenance rate and intravenous broad-spectrum antibiotics. The patient was placed in an oxygen cage at 40% oxygen and
was nebulized with sterile 0.9% saline solution for 15 minutes every eight hours, followed by gentle coupage.
Figure 7. The right caudal (left side of image) and accessory bronchi during expiration. There is partial collapse of both
DIAGNOSIS AND FOLLOW-UP CARE
Cytologic analysis of the bronchoalveolar lavage samples revealed normal findings (primarily alveolar macrophages) from the
right side. Severe purulent inflammation (many neutrophils and macrophages but no neoplastic cells or microorganisms) was
identified in the lavage sample from the left cranial lung lobe. These results, coupled with the findings from the bronchoscopy,
led us to a presumptive diagnosis of bronchopneumonia and lower airway collapse.
Bacterial cultures yielded Enterobacter cloacae growth from the left and right mainstem bronchial lavages. The patient was weaned off of oxygen and nebulization therapy
on the second and third days after admission and discharged on the fourth day with broad-spectrum antibiotics based on the
culture and sensitivity results. The owners were instructed to return for a recheck every two weeks until the pneumonia resolved.
Recheck examinations at two and four weeks revealed that the dog had continued clinical and radiographic improvement. Thoracic
radiographs at the 10-week recheck showed resolution of the pneumonia (Figures 8 & 9). Infrequent coughing was still present and was thought to be caused by continued bronchial collapse and subsequent airway
irritation, so an albuterol inhaler was prescribed to help decrease expiratory effort and potentially reduce bronchial collapse.
Antibiotic therapy was discontinued. Four weeks after initiating the albuterol inhaler, the owner reported that the dog had
decreased frequency of coughing.
Figure 8. A right lateral thoracic radiograph taken three months after initial presentation showing resolution of the previously
identified increased soft tissue opacity cranial to the heart. The previously described generalized cardiomegaly is relatively
Figure 9. A ventrodorsal thoracic radiograph taken three months after initial presentation showing resolution of the previously
identified alveolar pattern and unchanged generalized cardiomegaly.