Prevalence of canine infectious respiratory pathogens in asymptomatic dogs presented at US animal shelters

OBJECTIVES To determine the prevalence of nine canine infectious respiratory disease ( CIRD ) pathogens in asymptomatic dogs presented at animal shelters across the United States. METHODS Ocular and oronasal swabs from asymptomatic dogs ( n = 503) were tested using qPCR assay for Bordetella bronchiseptica , canine adenovirus type 2 ( CAV ‐2), canine distemper virus ( CDV ), canine herpesvirus type 1 ( CHV ), canine influenza virus ( CIV ), canine parainfluenza virus ( CPIV ), canine respiratory coronavirus ( CRCoV ), Mycoplasma cynos and Streptococcus equi subsp zooepidemicus . RESULTS A total of 240 (47 · 7%) asymptomatic dogs were PCR ‐positive for at least one CIRD pathogen. Prevalence of two‐, three‐, four‐, and five‐pathogen cases was 12 · 7, 3 · 8, 1 · 8, and 0 · 4%, respectively. Mycoplasma cynos (29 · 2%), B. bronchiseptica (19 · 5%), CAV ‐2 (12 · 5%), CDV (7 · 4%) and CPIV (3 · 2%) were the most commonly detected pathogens. CLINICAL SIGNIFICANCE The prevalence of traditional and newly emerging pathogens associated with CIRD is poorly defined in clinically healthy dogs. This study determined that a high percentage of asymptomatic shelter dogs harbor CIRD pathogens, including the newly emerging pathogen M. cynos and the historically prevalent pathogen B. bronchiseptica .