Canine parvovirus in Australia: A comparative study of reported rural and urban cases

Canine parvovirus (CPV) is a highly contagious and often fatal disease reported worldwide. Outbreaks occur throughout Australia, and it has been suggested that disproportionally more CPV cases occur in rural locations. However, evidence to support this suggestion-and possible reasons for such a predisposition-has not existed until now. In this study a total of 4870 CPV cases reported from an Australian disease surveillance system between September 2009 and July 2014 were analysed. Australian postcodes were classified as rural or urban (based on human population density) and reported CPV cases were then categorised as rural or urban based on their reported home postcode. Parvovirus cases were predominately young (<12 months), entire, unvaccinated, mixed-breed dogs. More than twice as many of the reported cases were from a rural area (3321 cases) compared to an urban area (1549 cases). The overall case fatality rate was 47.2%; it was higher for those CPV cases reported from urban areas (50.6%) than rural areas (45.5%). A greater proportion of rural cases were younger, entire dogs compared to urban cases. The final multivariable model of CPV cases being reported from a rural area included age (<12 months) and vaccination status (never vaccinated) as significant predictors. Poor socioeconomic status might be a reason for the decision of rural owners not to vaccinate their dogs as readily as urban owners. The excess reporting of rural CPV cases compared to urban cases and the predictive risk factors identified in this study can be used by veterinarians to reduce the incidence of CPV by educating owners about the disease and promoting better vaccination programs in rural areas. This study also supports that the increased risk of CPV in rural areas may necessitate a need for increased vigilance around preventing CPV disease spread, additional care with puppies which are the most susceptible to this disease and tighter vaccination protocols, compared to urban areas.