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.

【摘要】本文报告1例猫感染犬恶丝虫（Dirofilaria immitis）的病例，患猫临床表现为精神沉郁、厌食、呼吸困难、呼吸急促、轻度脱水及黏膜苍白。影像学检查显示心脏肥大、肺颅叶动脉扩张迂曲，尾叶动脉增大；肺实质右叶可见间质性肺浸润，且呈现向肺泡性浸润进展的征象。通过新鲜血液直接镜检、外周血涂片及克诺特改良试验（Knott’s modified test）检出的微丝蚴形态、运动特征，结合临床症状可支持该诊断。本文提请临床医师注意：在流行地区，当猫出现呼吸道症状时，需将猫心丝虫病（feline heartworm disease）纳入鉴别诊断范畴。