Prevalence of Bordetella bronchiseptica in dogs with respiratory disease

Abstract

Bordetella (B.) bronchiseptica is a well-known respiratory pathogen in dogs, frequently involved in the canine infectious respiratory disease (CIRD) complex. However, the bacterium has also been detected in the airways of healthy dogs. The aim of the study was to investigate the prevalence of B.bronchiseptica in upper and lower respiratory samples of dogs with and without respiratory disease and to compare the data between both groups of dogs. Twenty-six privately-owned dogs with different types of respiratory disease, and 16 dogs euthanized for non-respiratory illness with a physiological bronchoalveolar lavage fluid (BALF) cytology and no history or clinical signs of respiratory disease were included in the study. Culture and polymerase chain reaction (PCR) for B.bronchiseptica were performed on pharyngeal swabs and BALF of both groups. In the respiratory group, 31.8% (pharyngeal swabs) and 80.8% (BALF) of dogs were PCR-positive for B.bronchiseptica, while 50.0% (pharyngeal swabs) and 31.3% (BALF) of control dogs were positive. B.bronchiseptica was significantly more prevalent in the BALF of dogs with respiratory signs (p=0.003), while there was no difference in the results of pharyngeal swabs between groups (p=0.324). When detection methods were compared, PCR proved to be more sensitive than culture for detection of B.bronchiseptica (p < 0.001). Results confirm an association between B.bronchiseptica and respiratory disease in dogs. However, dogs without respiratory disease can also be carriers of the organism in the upper and lower airways, and quantification might be necessary to distinguish between colonization and infection.

Keywords

• Bordetella
• pneumonia
• CIRD
• kennel cough
• PCR