The Liverpool strain of the mosquito Aedes aegypti was infected with microfilariae of the canine heartworm, Dirofilaria immitis, and was used to transmit heartworm larvae to three dogs. Methods of confirming heartworm infection in these dogs included the modified Knott's test, a commercial enzyme-linked-immunosorbent assay (ELISA), an indirect fluorescent antibody (IFA) test, and post-mortem examination.