Isolation of Bordetella bronchiseptica in a dog with tracheal collapse

A 7-year-old male terrier was referred with a 3-week history of coughing, anorexia, lethargy, and weight loss to the clinic of small animals at the University of Tehran, Iran. On physical examination, cataracts were present in the eyes, nasal mucopurulent discharge, cyanotic mucous membrane, respiratory distress, tachypnoea, and increased abdominal expiratory effort were revealed, and a honking, productive cough was elicited on tracheal palpation. Auscultation of the trachea and lung fields revealed stertor and inspiratory wheeze, respectively. Hematologic findings included leukocytosis, characterised by neutrophilia with left shift, and normocytic, normochromic anaemia. Radiographic examination showed an alveolar pattern, especially in the medial lobe of the right lung. No other abnormality was found on radiographic examination. Bacteriological study on tracheal and lung specimens was performed, and Bordetella bronchiseptica was detected from the tracheal specimens. Based on the clinical history, physical examination, and bacteriological data, infectious tracheobronchitis (kennel cough) was diagnosed. Because of the severe respiratory distress and worsening of the clinical signs, further investigation and treatment were rejected by the owner, and the dog was euthanized. At necropsy, the trachea was collapsed along its entire length, and the tracheal membrane was loose and floppy. Probably, the presence of a concurrent tracheal infection with B. bronchiseptica (kennel cough) has been a triggering factor that caused clinical signs of tracheal collapse which developed in this dog.