Use of thoracoscopy to determine the etiology of pleural effusion in dogs and cats: 18 cases (1998-2001)

OBJECTIVE: To assess use of thoracoscopy to determine causes of pleural effusion in dogs and cats. DESIGN: Retrospective study. ANIMALS: 15 dogs and 3 cats with pleural effusion. PROCEDURE: Medical records were reviewed from 1998 to 2001 for dogs and cats that had exploratory thoracoscopy, biopsy, and histologic analysis to determine the etiology of pleural effusion. Intraoperative and postoperative complications were recorded. Surgical biopsy specimens were evaluated for quantity and quality for providing a histologic diagnosis. RESULTS: Biopsy specimens were deemed adequate in quantity and quality to render a histologic diagnosis in all animals. Etiology of the effusion was neoplasia in 8 animals and non-neoplastic pleuritis in 10 animals. Median survival time of animals with neoplasia was 15 days, whereas those with inflammatory diseases had median survival time of > 785 days. Postoperative pneumothorax was encountered in 2 animals subsequent to pulmonary biopsy. No other major complications were recorded. CONCLUSIONS AND CLINICAL RELEVANCE: Thoracoscopy is a diagnostic option that provides excellent viewing of intrathoracic structures and adequate biopsy specimens with minimal complications. This technique provides a less invasive alternative to thoracotomy for evaluating the etiology of pleural effusion.