Predominance of Canine Parainfluenza Virus and <i>Mycoplasma</i> in Canine Infectious Respiratory Disease Complex in Dogs

Abstract

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