2.1 Sample and data collection

Residual faecal samples from dogs with parvoviral enteritis diagnosed using a point-of-care (POC) faecal antigen ELISA, or qPCR performed at a commercial laboratory (VetPath, Perth), were collected. Samples were collected between March 2015 and August 2019 from five of Australia’s eight States and Territories (Figure 1). The patient’s age, breed, sex and postcode of origin were recorded. Postcode was used to derive region of origin defined by the Australian Government (Department of Infrastructure, Transport, Cities and Regional Development, 2018). Vaccination data obtained from medical records were used to assign cases to one of four categories: unvaccinated, incompletely vaccinated, completely vaccinated or unknown vaccination status. Completely vaccinated was defined as a dog that had received a puppy vaccination series comprising of at least two modified live virus (MLV) CPV vaccinations one month apart, with the last vaccination administered no earlier than 16-weeks of age, followed by a booster vaccine between 6 to 12 months of age, and revaccination every three years. Dogs less than 16-weeks of age that had received one or more CPV vaccinations were considered incompletely vaccinated (Day, Horzinek, Schultz, & Squires, 2016). Data obtained from patient medical records were used to classify each case according to whether treatment was given (treated or untreated), and whether the dog recovered, died or was euthanised.