Vascular, hepatic and renal lesions by Dirofilaria immitis invasion in dogs.

Morphological investigations were conducted on four bodies of dogs who died due to severe clinical symptoms following a massive invasion of cardiac and pulmonary Dirofilaria. The subjects were monitored clinically and diagnosed serologically positive for the Heartworm disease. The necropsy examination of the cardiovascular system (right ventricle and pulmonary artery) revealed the presence of 25 adult parasites in one dog with length ranging between 8 and 33cm. Macroscopically, lesions consistently observed were represented by the right ventricular dilatation and the diffuse wall thickening of the pulmonary artery. Parasitic invasion secondary lesions were present in the lungs, liver and kidneys (cardiac and vascular lesions). The histological examination mainly revealed myocardial injury, vascular (dystrophic), pulmonary (circulatory and inflammatory), hepatic (degenerative) and renal (degenerative and inflammatory) damage.