Disseminated Sporotrichosis in a Bilby (Macrotis lagotis)

Abstract

A male bilby (Macrotis lagotis) was presented to the Murdoch University Veterinary Anatomical Pathology Service following humane destruction due to severe lethargy. The bilby was emaciated with a focal ulcerated skin lesion on the dorsal tail base. Multifocal to coalescing foci of pyogranulomatous and often necrotizing inflammation was present within multiple organs, including the tail wound, adrenal glands, kidneys, lungs, brain, testes, lymph nodes, heart, liver, spleen and salivary glands. Admixed were abundant intrahistiocytic and extracellular pleomorphic yeast (round, oval and cigar-shaped) up to 6 μm diameter, often with a thin clear halo and occasional narrow-based budding. The diagnosis of disseminated sporotrichosis was confirmed via culture and sequencing of the internal transcribed spacer region of the causative agent, Sporothrix schenckii sensu lato. The route of entry of infection was considered most likely to have been via cutaneous inoculation of the tail base wound. To the authors' knowledge, this report describes the first known case of sporotrichosis in a native Australian animal.

Keywords: Macrotis lagotis; Sporothrix schenckii; fungal disease; marsupial.