Detection of selected viral pathogens in dogs with canine infectious respiratory disease in Austria

To assess the prevalence of canine parainfluenza virus, canine adenovirus type 2, canine distemper virus, canine respiratory coronavirus and influenza virus A infections in: (1) privately-owned or, (2) kennelled dogs showing signs consistent with canine infectious respiratory disease and, (3) clinically healthy dogs in Vienna, Austria.

Prospectively, nasal and tonsillar swabs from 214 dogs affected with infectious respiratory disease, and 50 healthy control dogs were tested for nucleic acids specific to the various viral infections. Concurrent bronchoalveolar lavage fluid from 31 dogs with chronic respiratory disease was investigated for the same viral pathogens. Additionally, anti-canine respiratory coronavirus antibody concentrations were measured in paired blood samples from 30 acutely diseased dogs.

Canine respiratory coronavirus (7.5%) and canine parainfluenza virus (6.5%) were the most commonly detected viruses in samples from the upper airways of dogs with respiratory infections. Serological results showed a significant seroconversion in response to coronavirus in 50% of the examined cases. None of the samples was positive for influenza virus A-specific nucleic acid. Canine coronavirus-specific nucleic acid was detected in 4.0% of healthy dogs.

Canine coronavirus should be considered as a clinically relevant cause of infectious respiratory disease in crowded dog populations. For sample collection, the nasal mucosa can be recommended as the favoured site. Analysis of paired serum samples aids verification of canine coronavirus infection in respiratory disease.