HISTOPATOLOGICAL ALTERATIONS IN LUNGS OF DOGS WITH PULMONARY DIROFILARIASIS IN THE STATE OF RIO DE JANEIRO, BRASIL

Abstract

The analysis, at light microscopy, of lungs histopathological alterations associated with the infection for Dirofilaria immitis in 33 (thirty three) dogs proceeding from Niteroi City, Rio de Janeiro, was carried out. A great diversity in number and intensity of lesions was observed. The most frequent pulmonary parenchyma changes had been interstitial pneumonia, interalveolar septa thickening and infartation, and the less had been focal fibrotic pleurisia and haemorrhage. Yet, in pulmonary artery and branches, the most frequent had been thrombosis and intimal proliferation to the lumen and the less had been pseudoaneurism and sclerosis. It was registered that in the presence of microfilariae in parenchyma, the infiltrates was predominantely formed for mononuclear cells, and in the destruction of the vessel wall, frequently for mixing or mononuclear cells. We concluded that more studies are necessary to the knowledge of the etiology and pathogenesis of Dirofilariasis, after recent studies that consider a bacterium endosymbionts of arthropods, Wolbachia, as the third variable, instead of the classic duality of  host–parasite  relationship.

KEY WORDS: Dogs, Dirofilaria immitis, histopathological alterations, lungs, pulmonary artery.