Mortality by Entamoeba invadens in green anacondas (Eunectes murinus) from a zoological garden

Five green anacondas (Eunectes murinus) from the same enclosure died sequentially in the zoological garden of the Federal University of Mato Grosso, Midwest Brazil. The primary lesions in all snakes were severe necrotizing enterocolitis and hepatitis, associated with intralesional positive-PAS trophozoites morphologically compatible with Entamoeba. The protozoa were randomly distributed in the intestine and liver of the five anacondas and in the stomachs, kidneys, and lungs of three anacondas. The snake enclosure had contact with the room next door, which housed alligators and turtles. Based on clinical history, gross and histopathological findings, and immunofluorescence test, which positively marked the respective trophozoites, it was concluded that Entamoeba invadens infected the anacondas.