Microfilaria can also be detected microscopically (service 234 Blood Parasites – microscopic).
In Europe alone, five different filarial species are known to cause filariasis in dogs: Dirofilaria immitis, Dirofilaria repens as well as Acanthocheilonema (Dipetalonema) reconditum, Acanthocheilonema (Dipetalonema) dracunculoides and Cercopithifilaria grassi. Dirofilaria immitis causes cardiovascular dirofilariasis (heartworm disease), Dirofilaria repens causes cutaneous dirofilariasis. Both types of dirofilariasis are zoonoses and are transmitted by mosquitoes, including the common house mosquito (Culex pipiens) which is very common in Germany. The mosquito genera Aedes and Anopheles are also competent intermediate hosts and vectors in Europe.