Fig. 2

Dogs surveyed for the presence of Dirofilaria immitis antigen in Australia. a Geographical distribution of dogs tested for heartworm as part of 2016–2019 prevalence surveys. The size of the circle at each location in New South Wales and Queensland (Central and Northern) is proportional to the number of tested dogs, number in brackets indicates number of D. immitis antigen positive dogs / total number of tested dogs. b Violin plots of distribution of age of 566 dogs sampled as part of four distinct cohorts, mean and quartiles are show within the violins. On the far left of the figure is a scatter dot plot of the individual ages of 13 antigen-positive dogs