Tropism and pathological findings associated with canine respiratory coronavirus (CRCoV)

Abstract

Canine infectious respiratory disease (CIRD) occurs frequently in densely housed dog populations. One of the common pathogens involved is canine respiratory coronavirus (CRCoV), however little is known regarding its pathogenesis and the role it plays in the development of CIRD. The pathogenesis of five geographically unrelated canine respiratory coronavirus (CRCoV) isolates was investigated. Following experimental infection in dogs, all five CRCoV isolates gave rise to clinical signs of respiratory disease consistent with that observed during natural infection. The presence of CRCoV was associated with marked histopathological changes in the nares and trachea, with loss and damage to tracheal cilia, accompanied by inflammation. Viral shedding was readily detected from the oropharynx up to 10 days post infection, but there was little or no evidence of rectal shedding. The successful re-isolation of CRCoV from a wide range of respiratory and mucosal associated lymphoid tissues, and lung lavage fluids demonstrates a clear tropism of CRCoV for respiratory tissues and fulfils the final requirement for Koch's postulates. By study day 14 dogs had seroconverted to CRCoV and the antibodies raised were neutralising against both homologous and heterologous strains of CRCoV in vitro, thus demonstrating antigenic homogeneity among CRCoV strains from the two continents. Defining the role that CRCoV and other agents play in CIRD is a considerable, but important, challenge if the disease is to be managed, treated and prevented more successfully. Here we have successfully developed a model for studying the pathogenicity and the role of CRCoV in CIRD.

European surveillance of emerging pathogens associated with canine infectious respiratory disease

“…Younger dogs (less likely to have antibodies to CRCoV) were more likely to be infected with CRCoV, and had a greater rate of occurrence of CIRD, and developed more severe clinical signs. These findings are consistent with previously published data (Erles et al, 2004(Erles et al, , 2003Mitchell et al, 2013a), and strengthen the evidence for a causal relationship between CRCoV infection and CIRD, as well as for the protective effect of CRCoV antibodies against both CRCoV infection and clinical signs of CIRD in general. Whilst evidence of CRCoV in pet dogs has been reported previously (Mochizuki et al, 2008;Priestnall et al, 2006) this is the first study to link infection to clinical disease in this group.…”

Bacterial Pneumonia in Dogs and Cats

“…Previous studies have implicated viral organisms such as canine adenovirus or canine parainfluenza 29 as major participants in CIRD, although recent studies have proposed novel respiratory pathogens such as canine respiratory coronavirus, 3,20,30,31 canine influenza virus, 20 and canine herpesvirus 32 as additional important pathogens associated with CIRD. B bronchiseptica, 33 Streptococcus canis, S equi subsp zooepidemicus, 29 and M cynos 3,34 have been implicated as secondary bacterial infections associated with CIRD.…”

Detection of non-primate hepaciviruses in UK dogs

“…Tracheal, lung and liver tissues were each assigned an overall histopathological score. For the trachea, a separate score was assigned for cilia morphology as described previously (Mitchell et al, 2013a). Briefly, scores were based on the severity and distribution of lesions, ranging from 0 (no significant histological abnormality recognised) to 4 (marked, extensive/ diffuse changes).…”