The geographic range of Angiostrongylus vasorum is expanding, leading to increased disease. Although observed cases of canine pulmonary angiostrongylosis have been dutifully reported in the literature, the state of biological knowledge remains too poor to predict future patterns of spread with any confidence. Nevertheless, there is an urgent need to identify areas that are likely to be suitable for parasite establishment. Preliminary attempts to do this using a climatic envelope approach suggest that several new areas are open to colonisation, even without invoking climate change. The risk of parasite importation into these areas should be mitigated, e.g. by restricting movement of dogs unless tested or treated for A. vasorum, and monitored by focused surveillance of definitive and intermediate hosts. These efforts will benefit from newly developed diagnostic tests.