Predominance of Canine Parainfluenza Virus and Mycoplasma in Canine Infectious Respiratory Disease Complex in Dogs

Canine infectious respiratory disease complex (CIRDC) is caused by different viruses and bacteria. Viruses associated with CIRDC include canine adenovirus-2 (CAV-2), canine distemper virus (CDV), canine influenza virus (CIV), canine herpesvirus (CHV), canine coronavirus (CCoV) and canine parainfluenza virus (CPIV). Bacteria associated with CIRDC include Bordetella bronchiseptica, Streptococcus equi subspecies zooepidemicus, and Mycoplasma spp. The present study examined the prevalence of pathogens associated with CIRDC in specimens received by a Veterinary Diagnostic Laboratory in Georgia from 2018 to 2022. Out of 459 cases, viral agents were detected in 34% cases and bacterial agents were detected in 58% cases. A single pathogen was detected in 31% cases, while two or more pathogens were identified in 24% cases. The percentages of viral agents identified were CAV-2 (4%), CDV (3%), CPIV (16%), CCoV (7%), and CIV (2%). The percentages of bacterial agents were Bordetella bronchiseptica (10%), Mycoplasma canis (24%), Mycoplasma cynos (21%), and S treptococcus zooepidemicus (2%). Positive viral cases ranged from 2-4% for CAV-2, 1-7% for CDV, 1-4% for CHV, 9-22% for CPIV, 4-13% for CCoV, and 1-4% for CIV. Overall, the study showed that the most prevalent pathogens associated with CIRDC during the study period were CPIV, M. canis, and M. cynos.