Primary Ciliary Dyskinesia with Secondary Pseudomonas aeruginosa Infection in a Dog: Endoscopic and Diagnostic Findings

A 7-month-old, 3.6-kg, intact male Dachshund was presented with a lifelong history of chronic respiratory signs. Multiple courses of antimicrobial therapy resulted in partial or complete clinical improvement, followed by recurrence after treatment discontinuation. To investigate the underlying cause of the persistent respiratory disease, rhino-tracheobronchoscopy was performed. Bronchoalveolar lavage (BAL) fluid and respiratory mucosal biopsy specimens were collected for cytological, histopathological, and ultrastructural evaluation. Cytological examination of BAL fluid revealed septic neutrophilic inflammation, and bacterial culture yielded P. aeruginosa. Transmission electron microscopy (TEM) identified ultrastructural abnormalities of the ciliary axoneme in 50% of the examined respiratory cilia. Based on these findings, primary ciliary dyskinesia (PCD) was diagnosed. PCD is a rare congenital disorder characterized by structural and functional abnormalities of motile cilia, resulting in impaired mucociliary clearance and recurrent respiratory infections. This case highlights the diagnostic value of a detailed clinical history, endoscopic examination, and TEM in dogs with suspected PCD.