As most hobbyists know, fungal infections are among the most common health problems to inflict captive amphibians and fishes. However, few realize that many species of fungus also attack lizards, turtles, snakes and other reptiles. Perhaps because, with the exception of skin fungi, infections are difficult to detect, treatment options are limited. However, some of the lessons we’ve learned in working with amphibians are helpful.
The Role of Stress
Fungi of one type or another are always present in the environment…many cause no problem at all until an animal’s immune system is weakened by stress. When I worked with birds at the Bronx Zoo, I learned that the stress of moving a bird from one exhibit to another frequently brought on an Aspergillus infection. This fungus is ever-present, but is easily handled by healthy immune systems. Green Iguanas and other reptiles have been found susceptible to Aspergillus as well; I would not be surprised if stress played a role as it does in birds.
Please be aware that stress is not limited to disturbing situations – overly hot or cold temperatures, poor lighting and other environmental factors all register as “stress” to the immune system. Other diseases also tax the immune system and thereby assist fungi in becoming established – in fact, secondary infection is perhaps the most common form of fungal attack.
Other fungi that have been observed in captive reptiles include Metarhizium, Penicillum and Candida.
Desert Adapted Reptiles
Reptiles that dwell in deserts or arid habitats are especially prone to fungal respiratory infections when kept in damp conditions. Some species (Egyptian Tortoises, in my experience) are very vulnerable when even a small amount of moisture is present in the substrate.
The enclosures of Chuckwallas, Pancake Tortoises, Desert Iguanas, Rosy Boas, Desert Tortoises and similar animals must be maintained carefully. It is best to keep such creatures on substrates specifically formulated for desert terrariums. Oyster shell, sold in bulk at garden supply shops, does not support the growth of fungi or mold, and is very useful for especially sensitive animals, or where problems have been noted in the past.
Despite adaptations to high humidity, reptiles hailing from rainforests and other damp habitats are not immune to fungal attack…in fact some, such as the Green Tree Python, are quite prone to infection when housed in poorly-ventilated cages.
Further information on Mycotic Disease from Infectious Diseases and Pathology of Reptiles.
Rosy Boa image referenced from wikipedia and originally posted by Shane O Pinnell