A retrospective study of the relationship between tracheal collapse and bronchiectasis in dogs.

Tracheal collapse is common in middle age toy and miniature breed dogs. Cartilaginous defects have been identified histologically and are considered a form of chondromalacia. In addition to tracheal cartilaginous changes, concurrent lower airway histologic changes indicative of inflammation have been noted in dogs with tracheal collapse and these changes may lead t o concurrent bronchiectasis. The purpose of this study was to investigate the prevalence of bronchiectasis in dogs with a previous radiographic diagnosis of tracheal collapse. The thoracic radiographs of 60 dogs with tracheal collapse were evaluated for evidence of concurrent bronchiectasis. Eighteen of 60 (30%) dogs had evidence of bronchiectasis, and all were cylindrical in morphology. The signalment of affected dogs was similar to that previously reported. The occurrence of bronchiectasis in this group of dogs with tracheal collapse (18 dogs) was six times higher (P < 0.05) than the expected prevalence within a random sample population (three dogs). The results of this study provide evidence of a link between tracheal collapse and bronchiectasis. A finding of bronchiectasis with tracheal collapse should encourage further evaluation for chronic lower airway disease in these patients.