European surveillance of emerging pathogens associated with canine infectious respiratory disease

Abstract

Canine infectious respiratory disease (CIRD) is a major cause of morbidity in dogs worldwide, and is associated with a number of new and emerging pathogens. In a large multi-centre European study the prevalences of four key emerging CIRD pathogens; canine respiratory coronavirus (CRCoV), canine pneumovirus (CnPnV), influenza A, and Mycoplasma cynos (M. cynos); were estimated, and risk factors for exposure, infection and clinical disease were investigated. CIRD affected 66% (381/572) of the dogs studied, including both pet and kennelled dogs. Disease occurrence and severity were significantly reduced in dogs vaccinated against classic CIRD agents, canine distemper virus (CDV), canine adenovirus 2 (CAV-2) and canine parainfluenza virus (CPIV), but substantial proportions (65.7%; 201/306) of vaccinated dogs remained affected. CRCoV and CnPnV were highly prevalent across the different dog populations, with overall seropositivity and detection rates of 47% and 7.7% for CRCoV, and 41.7% and 23.4% for CnPnV, respectively, and their presence was associated with increased occurrence and severity of clinical disease. Antibodies to CRCoV had a protective effect against CRCoV infection and more severe clinical signs of CIRD but antibodies to CnPnV did not. Involvement of M. cynos and influenza A in CIRD was less apparent. Despite 45% of dogs being seropositive for M. cynos, only 0.9% were PCR positive for M. cynos. Only 2.7% of dogs were seropositive for Influenza A, and none were positive by PCR.

Keywords: Canine infectious respiratory disease (CIRD); Canine influenza (CIV); Canine pneumovirus (CnPnV); Canine respiratory coronavirus (CRCoV); Kennel cough; Mycoplasma cynos.

Fig. 1

Proportion of vaccinated dogs with different clinical disease severity scores. Vaccinations: (Bb) Boredetella bronchiseptica, (CPIV) canine parainfluenza, (CAV-2) canine adenovirus-2, (CDV) canine distemper virus. The disease severity score is indicted on the x-axis by 1) Healthy, 2) mild to moderate, and 3) Severe respiratory disease. Error bars show 95% confidence interval. *Chi-squared/Fisher’s exact test p-value.