Clinical, pathologic, and ultrastructural features of situs inversus and immotile-cilia syndrome in a dog.

Situs inversus, rhinitis, and bronchitis were diagnosed in a 7-month-old male Golden Retriever. Electron microscopic examination of tracheal and bronchial biopsy specimens revealed 9% of the cilia with abnormal axonemal pattern and 1.2% with a fibrous ring between the circle of microtubular doublets and the cell membrane. A permanent response to treatment with antibiotics was not obtained and the dog was euthanatized. At necropsy the thoracic and abdominal organs were found to be in reversed position. Microscopic examination revealed evidence of chronic bronchitis as well as cystic and distended distal tubules of the kidneys. Foci of fibrosis were observed in the renal cortex. The diagnosis was immotile-cilia syndrome.