Mycotic Diseases of Reptiles EUiott R. Jacobson, DVM, PhD, Dip.ACZM, Joseph L. Cheatwood, BSM, and Lara K. Maxwell, DVM, PhD Numerous myotic diseases have been reported in rep- tiles. Although the integumentary system is most com- monly affected, systemic disease also occurs. The fungi commonly isolated from lesions in reptiles include Paecilomyces, Penicillium, Fusarium, Geotrichium, Mu- cor, and Aspergillus. Systemic mycotic diseases such as histoplasmosis, coccidiodomycosis, and cryptococcosis are rarely seen in reptiles. This review includes many of the known reports of mycoses in reptiles. Proper tech- niques for sampling and fungal culture are also pre- sented. Based on the limited information in the litera- ture, use of appropriate chemotherapeutics is discussed. Copyright 9 2000 by W. B. Saunders Company. Key words: Mycology, fungi, diseases, reptile. A variety of mycotic diseases have been re- ported in captive chelonians, crocodilians, and squamates. As far as the authors are aware, there are no reports describing mycotic disease in the tuatara (Sphenodon punctatus), a member of the order Rhynchocephalia. Relatively few mycotic diseases have been seen in free-ranging reptiles. As in other vertebrates, fungal patho- gens in reptiles may be primary or secondary invaders. Mycotic disease may be associated with predisposing factors including high humidity, overcrowding, and debris accumulation in the animal's environment. The system affected may vary between the major groups of reptiles. For instance, whereas mycotic pneumonia is uncom- mon in snakes, it is commonly seen in captive chelonians. Compared with mammals, systemic mycotic diseases such as histoplasmosis, coccid- iodomycosis, and cryptococcosis are rarely seen in reptiles. Similarly, the dermatophytes Trichophy- ton and Microsporum are rarely reported in rep- tiles. In contrast, fungi that are seldom reported as significant problems in birds and mammals are common in reptiles. Beginning with an From the Department of Small Animal Clinical Sciences, College of VeterinaryMedicine, Universityof Florida, Gainesville,FL. Address reprint requests to Elliott R. Jacobson, DVM, PhD, Box 100126, Department of Small Animal Clinical Sciences, Collegeof VeterinaryMedicine, Universityof Florida, Gainesville,FL 32610. Copyright 92000 by W. B. Saunders Company. 1055-937X/00/0902-0006510. 00/0 doi:10.1053/AX.2000. 4621 overview of fungal taxonomy, we will review the literature on fungal infections of reptiles, diagnos- tic techniques, and therapy. Fungal Taxonomy Many different fungi have been identified in the tissues of humans (and other mammals), reptiles, and birds. Almost any fungus can be a facultative pathogen, moving into preexisting lesions and preying on soft tissues of immuno- compromised patients. However, some fungi are primary pathogens, causing damage to healthy tissue without the aid of other organisms. These primary pathogens are considered medically important. All fungi are members of the kingdom Fungi (Myceteae). Most pathogenic fungi are classified in the division Amastigomycota. Within this divi- sion, there are seven classes containing medically important fungi. Table 1 shows the taxonomic breakdown in greater detail, listing genera in each family that are known human pathogens. There are hundreds of fungi that have been shown to be of medical importance. Because appropriate therapies differ for various patho- gens, it is important to rapidly and accurately identify fungi. Morphological characteristics, such as width of hyphae, presence or absence of septae, type and size of reproductive structures, colony morphology (including size, shape, rate of growth, and color), and optimum incubation temperature are used to identify and classify fungi. These characteristics are explained in more detail in many medical and clinical mycol- ogy reference books. 1,2 It is important to consult the most recently published reference books to ensure that the most current techniques and products are used for fungal identification and that the most widely accepted names are used. Review of Literature by Order of Reptiles Chelonia Hyalohyphomycosis. Hyalohy-phomycosis is a term that includes mycotic infections involving 94 Seminars in Avian and Exotic Pet Medicine, Vol 9, No 2 (April), 2000: pp 94-101