Fig. 3

Histogram of published studies on Dirofilaria immitis in Australia from 1901 to 2019. All articles were manually inspected to confirm the presence D. immitis data in Australia (red, n = 98) and studies reporting prevalence data of D. immitis were identified (blue, n = 32). Inclusion criteria for retained references included primary data on D. immitis prevalence in dogs, regardless of the method used