Topographical distribution and radiographic pattern of lung lesions in canine eosinophilic bronchopneumopathy

To evaluate the radiographic lung pattern and topographical distribution in canine eosinophilic bronchopneumopathy.

Medical records were retrospectively reviewed for dogs diagnosed with eosinophilic bronchopneumopathy. Lateral thoracic radiographs were examined for the presence of increased radiopacity, classification of pattern, topography of lung changes (cranioventral, perihilar, caudodorsal, caudoventral) and severity of pulmonary lesions.

Forty-four cases were identified with the Labrador retriever being the most commonly affected breed; there was a mean age of 5 years and an equal gender distribution. Coughing was the most common clinical sign. Circulating eosinophilia was present in 39% of dogs, with a mean peripheral eosinophilia of 5.1×10⁹ cells/L and a mean bronchoalveolar lavage fluid eosinophilia of 40%. Eighty percent of dogs had an abnormal lung pattern in at least one of the four lung fields; the remaining had normal thoracic radiographs. The most common patterns were a bronchial and a bronchointerstitial pattern, with 41 and 89% distribution to the caudodorsal lung field, respectively.

A bronchial and bronchointerstitial pattern are the most common radiographic lung patterns seen in canine eosinophilic bronchopneumopathy with these patterns most frequently topographically distributed to at least the caudodorsal lung field. Furthermore, within the caudodorsal lung field, a bronchointerstitial pattern predominates. This radiographic and topographical finding may allow eosinophilic bronchopneumopathy to take precedence on a differential diagnoses list before confirmatory bronchoalveolar lavage fluid sampling.