[Granulomatous pleuritis and chylothorax caused by calcite inhalation in a Galgo Español dog]

A 6-year-old, male Galgo Español dog was presented with severe dyspnea. Radiography and ultrasonography revealed pleural effusion. Approximately 4 l of a milky and slightly reddish fluid were aspirated and drained from the thoracic cavity. Clinical chemistry examination of the fluid indicated a modified transudate with a high amount of triglycerides. On cytological examination, degenerated neutrophilic granulocytes, small lymphocytes, macrophages and chylomicrons were found. A chest tube was placed and computed tomography was performed, which indicated thickening of parietal and visceral pleura and enlargement of the sternal lymph node without abnormal findings in the lungs. During subsequent thoracoscopy disseminated proliferative masses, appearing as small white nodules, covering nearly the entire pleural surface were found and biopsies were taken for further analysis. Histopathologic diagnosis was a granulomatous pleuritis with intralesional birefringent foreign material. Energy dispensive x-ray emission analysis was used to determine the origin of the material. Scanning electron microscopy revealed high amounts of calcium containing foreign material (calcite) within the granulomas. An extended clinical history of the dog gave evidence that the animal had lived next to a construction site 15 months earlier and may well have inhaled the calcium-containing dust. Treatment with prednisolone was initiated, however the dog developed gastro-intestinal side effects and treatment was stalled after 10 weeks. Dyspnea and liquidothorax re-occurred 4 months later. A further attempt of immunosupressive treatment was commenced, using a combination of prednisolone and ciclosporine, which again was not tolerated by the patient. The dog finally developed pneumonia and was euthanized by the owner's request.