Chromomycosis in a Marine Toad, Bufo marinus
Assoc Reptilian Amphibian Vet 7[3]:13-15 Winter'97 Case Report 14 Refs

- An adult male, wild-caught, marine toad, Bufo marinus, weighing 310 g, was presented with a three day history of having a small swelling on the left maxilla. Physical examination revealed a raised, ulcerated lesion measuring 5 mm in diameter. Aerobic culture revealed moderate growth of a mixed population of Gram-negative rods, with no predominance. Anaerobic culture was not performed. The lesion was infiltrated with 1% lidocaine and removed with electrosurgery. Several impression smears of the lesion, stained with a Wright-Giemsa method, revealed accumulations of mononuclear cells surrounding pigmented, septate fungal hyphae (Fig. 2). One half of the mass was preserved in 10% formalin solution, embedded in paraffin, sectioned at 5um and stained with hematoxylin and eosin. The remaining tissue was submitted for fungal culture. Additional treatment was initiated with itraconazole at 5mg/kg PO q 48 hours for 30 days. The surgical site healed by second intention and no recurrence of lesions was noted after treatment. Histopathology reported multifocal granulomas containing macrophages, lymphocytes, plasma cells and occasional multinucleated giant cells were noted within the dermis. Within the granulomas, pigmented, septate fungal hyphae were noted (Fig.3). Chromomycosis is a term used to describe infections with pigmented fungi of the family Dematiaceae. Fungal infections, including chromomycosis are common infections of reptiles and amphibians. It can present as ulcerated or granulomatous skin lesions and/or disseminated granulomas within visceral organs. Antemortem diagnosis is difficult, and serological tests for Dematiaceae do not appear to be available. Treatment in amphibians had been generally unsuccessful, but in this case, the combination of electrosurgery and itraconazole appeared to be successful regime. Impressions smears allowed rapid diagnosis which was confirmed on histopathy. Two years after treatment, the toad remains clinically asymptomatic.