Genetic evolution of canine coronavirus and recent advances in prophylaxis

Abstract

-Since the first identification of the virus in 1971, the disease caused by canine coronavirus (CCoV) has not been adequately investigated and the role that the virus plays in canine enteric illness has still not been well established. In the last decade, as a consequence of the relatively high mutation frequency of RNA positive stranded viruses, CCoV has evolved and a new genotype has been identified in the faeces of infected dogs. The several studies carried out by different researchers have focused upon the epidemiological relevance of these viruses and, considering the wide diffusion of CCoV infections among dog populations, the author underlines the need for further investigation on the biology of CCoV and on the pathogenetic role of their infections.

Canine coronavirus (CCoV) in dogs vaccinated and unvaccinated domiciliated in Pelotas, RS, Brazil

“…The primary means of transmission is via exposure of susceptible hosts to virus shed in feces (CARMICHAEL; BINN, 1981). Infected dogs generally shed CCoV in the feces for 6-9 days post infection, but some naturally infected dogs have shed virus for a period as long as 6 months after clinical signs had ceased (PRATELLI, 2006). In this study, infection in most of the animals may have happened due to environmental exposure.…”

“…CCoV is highly contagious and once the virus has become established in the environment, the spread of the infection is difficult to control. Avoiding contact with infected dogs and their excretions is the only way to ensure disease prevention (PRATELLI, 2006). There was not a significant association between seropositivity and parameters evaluated (sex, age, habitat that would allow contact with other animals and season of collection), suggesting low but continuing exposure to CCoV in all categories analyzed.…”

“…Although the efficacy and the duration of immunity engendered by inactivated vaccines have not been substantiated, only killed CCoV vaccines have been licensed in Brazil. Modified life (ML) vaccines have been licensed in the past, but they often resulted in a high frequency adverse of post-vaccinal reactions (SAIF, 1993;PRATELLI, 2006). …”

Exposure of pampas fox (Pseudalopex gymnocercus) and crab-eating fox (Cerdocyon thous) from the Southern region of Brazil to Canine distemper virus (CDV), Canine parvovirus (CPV) and Canine coronavirus (CCoV)

“…The lower frequency of CCoV compared with CPV, was probably due to the biological characteristics of this virus. Although for both the viruses the transmission occurs mainly by exposition of susceptible animals to the virus eliminated through feces of infected animals (Pratelli, 2006), CCoV is less persistent in the environment and can be excreted in feces in smaller quantities than CPV. This study showed the serologic evidence that free-ranging pampas foxes (P. gymnocercus) and crab-eating foxes (C. thous) from Southern region of Brazil were exposed to Canine distemper virus (CDV), Canine parvovirus (CPV) and Canine coronavirus (CCoV).…”

Molecular stability of a vaccine strain of Canine coronavirus after serial passages in A72 cells

“…(Nidovirales: Coronaviridae: Coronavirinae) (DE GROOT et al, 2013) and evolutionary studies on Alphacoronavirus-1 have demonstrated that some geno-/serotypes of these viruses emerged as a result of recombination events between each other (PRATELLI et al, 2004;PRATELLI, 2006;DECARO et al, 2009).…”