Intestinal mucormycosis in a captive tiger

Mucormycosis is an angioinvasive fungal infection caused by ubiquitous saprophytic fungi of the order Mucorales. In humans, the infection is generally caused by inhalation of spores or traumatic inoculation in cutaneous wounds, typically affecting immunocompromised patients. In animals, Mucorales infection is common in cattle, but is rare in the other species, including felids. No cases of mucormycosis have been reported to date in non-domestic felids, to our knowledge. We describe a case of mucormycosis in a 5-y-old female captive tiger (Panthera tigris). The affected tiger was part of a group of 9 subjects, 7 of which had serohemorrhagic nasal discharge, anorexia, and depression, followed by hemorrhagic diarrhea. Five of the tigers died and organs from one animal were sent for histologic examination, which revealed severe necrohemorrhagic enteritis, with periodic acid-Schiff– and Grocott methenamine silver–positive fungal hyphae. Mucor colonies were cultured from sawdust, which served as litter for the animals, indicating a possible source of infection through inhalation of spores and/or ingestion of contaminated sawdust. Mucormycosis is a possible differential for necrohemorrhagic enteritis in captive felids; careful storage and periodic assessment of the materials used as litter for these animals is recommended.