Pathogenesis and Transmission
Similar to Dirofilaria immitis, D. repens third stage larvae (L3) are transmitted to the dog during blood feeding of a mosquito (mainly Anopheles and Aedes, but also Culex species). Inside the vertebrate host, the larvae develop and mature to the adult form, which then produces its offspring, the so-called microfilariae. Mosquitoes become infected with microfilariae while taking a blood meal from an infected animal. Finally, the nematode larvae develop inside the ectoparasite to L3, which can then enter the next mammal. Inside the vertebrate, adult D. repens individuals settle predominantly in subcutaneous or in connective tissues.