Hidden Reflux: 75% of Dogs With Respiratory Disease Have Silent Swallowing Abnormalities

Use of thoracic computed tomography to aid in classification of final diagnosis in dogs with respiratory disease based on airway, parenchymal or mixed airway and parenchymal involvement. (A, B) Transverse and dorsal sections from a 6-year-old MC Siberian Husky with airway disease. Note the marked peribronchovascular thickening creating an appearance of peribronchial cuffing in cross-section. Bronchiectasis was noted by dilatation and lack of tapering of airways traversing to the periphery. The final diagnoses were eosinophilic bronchitis and bronchiectasis. (C, D) Transverse and dorsal sections from a 10-year-old FS Labrador retriever with parenchymal disease. Note the extensive regions of consolidation. Histology and response to immunosuppression confirmed an immune-mediated lung disease. (E, F) Paired ventilator-assisted inspiratory: expiratory breath hold transverse sections from an 11-year-old MC French bulldog with both airway and parenchymal disease substantially contributing to clinical signs. On the inspiratory series, increased peribronchovascular thickening and focal consolidation (*) are noted. On the expiratory series, the caliber of the segmental and subsegmental airways are smaller than on the inspiratory series with a corresponding loss of lung volume and presence of more global ground glass opacity because of downstream effects of bronchomalacia. The previously noted region of consolidation (*) remains present. The final diagnoses included brachycephalic obstructive airway syndrome, bronchomalacia, aspiration pneumonia, and suspect pulmonary fibrosis (corresponding lesions not shown). (G, H) Transverse images from a 13-year-old FS French bulldog with predominating airway lesions and mild, focal evidence of parenchymal disease. In (G), ground glass opacification in the mid-zone of the lung (within the white box), with Hounsfield units ranging from −425 to −550. The white arrows on the right side of the figure show bronchiectatic airways. Further evidence of cylindrical bronchiectasis is seen in (H) with a lack of tapering as shown by the white arrows. Using data from the clinical picture and other advanced diagnostics, the final diagnoses were chronic bronchitis, bronchiectasis, mainstem bronchial collapse, hiatal hernia, and uncharacterized parenchymal disease. (I-L) Transverse images from a 14-year-old FS Pomeranian with predominating parenchymal disease and a lesser contribution of airway disease. In (I) taken from the expiratory series, grade II tracheal collapse is demonstrated by a 50% reduction in luminal diameter with a flattened shape. In (J), the box outlines a region of architectural distortion characterized by traction bronchiectasis/bronchiolectasis superimposed on a background of reticulation and ground glass opacity, compatible with pulmonary fibrosis. In (K) and (L), there are multifocal regions of ground glass opacity and consolidation (*). Final diagnoses were grade II tracheal collapse, grade I mainstem bronchial collapse, grade I bronchomalacia, extra-esophageal reflux, suspect pulmonary fibrosis, and uncharacterized parenchymal disease.