School of Biological Sciences, University of Bristol, Woodland Road, Bristol, UK, BS8 1UG. eric.morgan@bristol.ac.uk <eric.morgan@bristol.ac.uk>
Recent reports suggest that the canine heartworm Angiostrongylus vasorum is expanding from traditional endemic foci in several parts of the world. We are ill placed to judge the causes and potential consequences of this expansion because of a lack of knowledge about fundamental aspects of the biology of the parasite. We call for a renewed focus on this important but neglected nematode.