Canine parvovirus epidemiology in Australia: prevalence, risk factors, and strategies to control and prevent disease

Abstract

The overall aim of this research was to gain an understanding of canine parvovirus (CPV) prevalence and caseload in Australia, to identify the populations at risk of disease and gain a better understanding of the risk factors for CPV disease and mortality. A secondary objective was to begin to develop strategies to help control and prevent disease cases. In 2017 a national online veterinary survey was launched to determine CPV prevalence and identify disease case locations, and to understand the role that euthanasia plays in CPV mortality, and the influence of cost of disease treatment on mortality rate. Socioeconomic, geographic and climatic risk factors for CPV infection and euthanasia in Australia were then investigated. Veterinarian perceptions of CPV prevalence, their preventive behaviours, and the influence of socioeconomics, remoteness, CPV caseload and demographics on these behaviours was also assessed. Lastly, wild dog cadavers were tissue-sampled to determine if CPV transmission occurs between these dogs and domestic dogs. Survey respondents reported 4,219 CPV cases in 2016; the estimated national case load was 20,110. Overall, reported euthanasia rate was 41%. Rural and remote areas were at highest CPV risk, and a strong correlation was found between CPV treatment cost and euthanasia rate without treatment. Case reporting, case numbers, and without-treatment euthanasia were significantly associated with socioeconomic disadvantage. Overall, veterinarians underestimated national CPV caseload, particularly hospitals that did not diagnose CPV cases. Perceived disease mortality (50%) was 2.74 times higher than reported (18.2%). Nearly half (48.7%) of respondents recommended final puppy vaccination earlier than guidelines recommend, which may put puppies at risk. CPV DNA was detected in 4.7% of wild dogs and a strong geospatial association was found between wild-dog CPV infections and domestic-dog CPV cases reported to a national disease surveillance system.