Dirofilaria immitis parasite infection in cats: first case reported in the Legal Amazon region, Brazil - case report

ABSTRACT A case of infection with Dirofilaria immitis in a cat is reported here with clinical signs of apathy, anorexia, dyspnea, polypnea, slight dehydration and pale mucus membranes. The radiographic examination showed cardiomegaly, lobar arteries dilation of the cranial lobes and tortuosity, enlargement of the caudal lobar arteries. In the right lobe of the lung parenchyma, interstitial pulmonary opacification tending to alveolar opacification was seen. The clinical signs, the movements, and the morphology of the microfilariae in the direct examination of fresh blood, peripheral blood smear and Knott’s modified test supported the diagnosis. We alert to the need for clinicians to consider feline heartworm diseases as a differential diagnosis in endemic areas when cats show respiratory signs.