Figure 1.

a) Glomerulus characterized by irregular basement membrane thickening and mild proliferation of mesangial cells and minimal sclerosis (PAS, ×600); b) The small oral orifice of D. immitis, with the presence of aring and without lips; c) Rounded posterior extremity of an adultmale of D. immitis, with spicules markedly unequal, numerous caudal papillae (black arrows) and crest and striations in the ventral surface (white arrow); d) Microfilaria of D. immitis with a pointed anterior extremity and a straight tail. Many embryos of microfilariae (black square) were observed in the blood collected from the right ventricle of the heart.