Immunocompromised mouse strains that lack adaptive immunity pathways like RAG2−/− (27, 28), IL-4/5−/− (32) and NSG strains (26, 36) have been proven suitable for human filarial infections and recently, NSG mice have been also proven to be susceptible to infection with the dog heartworm Dirofilaria immits (47, 48). Here, IL4 is linked to infection.