Dirofilariasis - epidemiology, Dirofilaria immitis - isolation & purification, Dog Diseases - parasitology, Dog Diseases - epidemiology, Parasitemia - epidemiology, Dirofilariasis - parasitology, Culicidae - parasitology, Microfilaria - isolation & purification, Parasitemia - parasitology, Parasitemia - veterinary, Insect Vectors - parasitology, Portugal, Kn...