Angiostrongylosis inCerdocyon thous(crab-eating fox) andLycalopex gymnocercus(Pampas fox) in Southern Brazil

Abstract

The objective of this study was to identify species of Angiostrongylus spp. infecting wild carnivores in Southern Brazil, as well as to describe gross and histopathological findings associated with the infection. Necropsy was conducted in 16 wild carnivores parasitized by Angiostrongylus spp. Analysed lungs revealed multifocal dark-red areas of consolidation; in one case, multifocal firm white nodules spread in all pulmonary lobes were observed. In one animal, a focally extensive area of malacia associated with haemorrhage was noted in the encephalon. Histologically, multifocal granulomatous pneumonia or bronchopneumonia, associated with eggs and larvae in blood vessels, lung interstitium, alveoli, and sometimes in bronchi and bronchioles was observed. Adult nematodes were seen within blood vessels. The lesion observed in the brain was characterized as a focally extensive area of malacia associated with gitter cells, haemorrhage, thrombosis and a free intralesional larva. Through molecular techniques, seven positive samples of Angiostrongylus cantonensis were obtained, including the brain sample, and a positive sample of Angiostrongylus vasorum-like, all in Cerdocyon thous. The positive sample for A. vasorum showed 97% similarity with sequences deposited in GenBank, suggesting a new species or subspecies of Angiostrongylus sp. Infection of Lycalopex gymnocercus by Angiostrongylus spp. was confirmed by histological evaluation.