This week’s case is a 15-year-old Pembroke Welsh Corgi with recent intermittent episodes of dyspnea. What pattern is present, and what are your differential diagnoses?
On radiographs of the thorax, there is a diffuse mixed interstitial to alveolar pattern throughout the lungs. with a bronchial component. The opacity outlines the airways and partially obscures the cardiac silhouette on the dorsoventral projection. The cardiac silhouette is more visible on the ventrodorsal projection and appears normal.
The mixed pulmonary pattern is most likely due to degenerative disease such as fibrosis or pulmonary edema from vasculitis or ARDS. However, inflammatory disease or neoplasia cannot be completely ruled out.
Lung pathology revealed marked septal fibrosis with multiple peripheral bullae. There was also marked alveolar histiocytosis and interstitial pneumonia, with mild edema.