An adult male Aldabra tortoise (Geochelone gigantea) presented with large flaking areas of the carapace, and biopsy of these areas revealed chromomycosis. After initial debridement, underlying tissue was brown. Histopathology revealed variably degenerative keratin extensively colonized by short beaded brown pigmented fungal elements consistent with chromomycosis. The disease progressed rapidly and spread to numerous sites on the carapace. After several weeks of regular debridement, bone involvement was evident. Histopathology then revealed necrotic bone colonized by pigmented spherical fungal elements, some of which were associated with elongated hyphae-like pigmented structures. Fungal culture grew Fonsecaea pedrosoi, a common pathogen of chromomycosis in humans. Initial treatment included oral itraconazole (Patriot Pharmaceuticals, Plymouth Meeting, PA 19462 USA) and topical terbinafine hydrochloride (Lamisil AT, Novartis Pharmaceuticals, Parsippany, NJ 07054 USA). Oral terbinafine hydrochloride (Lamisil, Novartis Pharmaceuticals) and a 2.5% fluconazole in dimethyl sulfoxide topical suspension (compounded by Nora Apothecary, Indianapolis, IN 46240 USA) were used later in treatment. The animal has been scheduled for a nuclear scintigraphy bone scan to determine the extent of the lesions with possible subsequent deep surgical debridement.
This disease is commonly reported in amphibians3 and humans4 but has rarely been reported in chelonians.1,2 This is the first reported case of chromomycosis in a tortoise shell.
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