Co-infections with Respiratory Viruses in Dogs with Bacterial Pneumonia

Viitanen, S.J.; Lappalainen, A.; Rajamäki, M.M.

A full clinical examination was performed, with special emphasis on the respiratory tract. Thoracic radiographs (laterolateral and ventrodorsal or dorsoventral views) were obtained at presentation and assessed by the same radiologist (AL), who was blinded to the patient data. Hematology, serum biochemistry, serum Creactive protein (CRP) and fecal analysis were performed. Arterial blood gas analysis for partial pressures of oxygen and carbon dioxide were measured and the alveolar-arterial gradient was calculated. Bronchoscopy was performed with a 4.9-mm flexible endoscope, a and airway samples for cytology, semiquantitative aerobic and anaerobic bacterial culture, qualitative Mycoplasma spp. culture and PCR analysis were obtained by weight-adjusted (1 ml/ kg 0.9% NaCl) bronchoalveolar lavage (BAL). 45 Transtracheal wash (TTW) sampling was used in dogs with BP in which anesthesia was considered unsafe because of the severity of the disease. 46 Bacterial pneumonia was diagnosed when there were typical acute signs (at least 3 of the following: fever, lethargy, dyspnea, tachypnea, cough) and findings compatible with BP on thoracic radiographs. 1, 42, 43 A bacterial origin was proved by cytological confirmation of bacterial infection in respiratory samples (>2 intracellular bacteria/oil immersion field), positive bacterial culture (≥10 3 colony-forming units/mL in airway samples), 47 or rapid response to antibiotics and full clinical and radiographic normalization with antibiotic treatment. All dogs with BP were followed until full cure. Prolonged BBTB was diagnosed when there was a cough lasting for >30 days and a positive bacterial culture of B. bronchiseptica (>10 3 colony-forming units/mL) in bronchoalveolar lavage fluid (BALF) and an absence of other diagnosed airway pathology.