Detection of respiratory viruses and Bordetella bronchiseptica in dogs with acute respiratory tract infections

Abstract

Canine infectious respiratory disease (CIRD) is an acute, highly contagious disease complex caused by a variety of infectious agents. At present, the role of viral and bacterial components as primary or secondary pathogens in CIRD is not fully understood. The aim of this study was to investigate the prevalence of canine parainfluenza virus (CPIV), canine adenovirus type 2 (CAV-2), canine influenza virus (CIV), canine respiratory coronavirus (CRCoV), canine herpes virus-1 (CHV-1), canine distemper virus (CDV) and Bordetella bronchiseptica in dogs with CIRD and to compare the data with findings in healthy dogs. Sixty-one dogs with CIRD and 90 clinically healthy dogs from Southern Germany were prospectively enrolled in this study. Nasal and pharyngeal swabs were collected from all dogs and were analysed for CPIV, CAV-2, CIV, CRCoV, CHV-1, CDV, and B. bronchiseptica by real-time PCR. In dogs with acute respiratory signs, 37.7% tested positive for CPIV, 9.8% for CRCoV and 78.7% for B. bronchiseptica. Co-infections with more than one agent were detected in 47.9% of B. bronchiseptica-positive, 82.6% of CPIV-positive, and 100% of CRCoV-positive dogs. In clinically healthy dogs, 1.1% tested positive for CAV-2, 7.8% for CPIV and 45.6% for B. bronchiseptica. CPIV and B. bronchiseptica were detected significantly more often in dogs with CIRD than in clinically healthy dogs (P < 0.001 for each pathogen) and were the most common infectious agents in dogs with CIRD in Southern Germany. Mixed infections with several pathogens were common. In conclusion, clinically healthy dogs can carry respiratory pathogens and could act as sources of infection for susceptible dogs.

Prevalence of respiratory pathogens detected in dogs with kennel cough in Poland

“…In all animals, at least one of the infectious agents was detected, and in most cases (65%) co-infections were confirmed. These results are in contrast to those obtained in studies carried out in the UK, Japan, and Thailand, where co-infections accounted for no more than 15%, and in Germany, where they accounted for approximately 37% of animals with kennel cough symptoms (Erles et al 2004;Mochizuki et al 2008;Posuwan et al 2010;Schulz et al 2014). One of the reasons for the discrepancy between findings may be the fact that in our study co-infections were primarily caused by the combination of CHV and another pathogen, which may indicate a chronic form of the disease.…”

“…In a study carried out by in India, this microorganism was only found in 2 out of 68 dogs exhibiting kennel cough symptoms. A different situation was reported in Germany, where the presence of Bordetella bronchiseptica was confirmed in as many as 78% symptomatic dogs, and in most cases it was the only isolated infectious agent (Schulz et al 2014). The results obtained in our study may indicate that this bacterium is an important aetiological factor of kennel cough, although not the most frequent one in Poland.…”

“…These results are partially consistent with those obtained in other countries. In the UK CHV was identified as the second most prevalent pathogen in animals with kennel cough (Erles et al 2004), but in Germany the presence of this virus was confirmed neither in healthy dogs nor in those exhibiting clinical symptoms (Schulz et al 2014). Even though CHV is mentioned as one of the infectious agents of kennel cough, its role and importance in the aetiology of this disease is not fully understood, and is still very controversial.…”

“…Numerous studies monitoring the aetiological factors of kennel cough have shown that CPIV virus is very frequently detected in dogs with this disease around the world. Therefore, the high prevalence of CPIV RNA in the analysed samples should not come as a surprise (Erles et al 2004;Mochizuki et al 2008;Posuwan et al 2010;Schulz et al 2014). On the other hand, a vaccine containing an attenuated CPIV strain is commercially available in Poland, so the high prevalence of this virus in such a large number of dogs with kennel cough may be considered alarming.…”

Detection and molecular characterization of canine adenovirus type 2 (CAV-2) in dogs with respiratory tract symptoms in shelters in Turkey

“…SCHULZ et al (2014) have reported that in addition to CAV-2, canine parainfluenza virus, canine influenza virus, canine respiratory coronavirus, as well as B. bronchiseptica were detected in varying rates among the shelter and the owned dogs, with or without acute respiratory system infection. Further, the presence of B. bronchiseptica was significantly higher in dogs with clinical respiratory infection than in the healthy looking dogs (45.6% and 78.7%, respectively); there was a high prevalence of multiple infections.…”