Snake fungal disease (SFD) is caused by Ophidiomyces ophiodiicola. SFD has been linked to population declines of wild timber rattlesnake (Crotalus horridus) and a threat to Eastern Massasauga (Sistrurus catenatus) populations.1,3 A retrospective review of all mycotic infections that were confirmed via biopsy or necropsy in captive snakes from 1983 to 2017 was performed at the Smithsonian’s National Zoological Park (NZP). Thirty-seven mycotic infections were identified and 32% (n=12) of those cases were confirmed to be SFD via quantitative polymerase chain reaction (qPCR) on paraffin block sections.2 Infections with SFD were evenly distributed over the 35-year-period. There was a period prevalence of 3.87% of completed snake necropsy cases that were SFD positive. Species affected were green anaconda (Eunectes murinus) n=4, garden tree boa (Corallus hortulanus) n=1, false water cobra (Hydrodynastes gigas) n=4, yellow anaconda (Eunectes notaeus) n=1, Eastern milk snake (Lampropeltis triangulum) n=1, and an Eastern diamondback rattlesnake (Crotalus adamanteus) n=1. Histopathology from all cases showed mycotic epidermitis/dermatitis (n=10), mycotic pneumonia (n=4), and subcutaneous/intramuscular fungal granuloma (n=1). To date no old-world snake species has been diagnosed with SFD at NZP. Snake fungal disease appears to be a disease that was/is under or misdiagnosed in captive snakes until molecular testing became readily available. As qPCR is an accurate method of evaluating snakes with suspected fungal lesions, it is recommended that any suspicious lesions on histopathology or physical examination be tested for SFD and appropriate biosecurity measures be taken to prevent further spread of the disease in collection animals.
1. Allender MC, Bunick D, Dzhaman E, Burrus L, Maddox C. Development and use of a real-time polymerase chain reaction assay for the detection of Ophidiomyces ophiodiicola in snakes. J Vet Diagn Invest. 2015;27(2):217–220.
2. Allender MC, Dreslik M, Wylie S, Phillips C, Wylie DB, Maddox C, et al. Chrysosporium sp. Infection in Eastern massasauga rattlesnakes. Emerg Infect Dis. 2011;17(12):2383–2384.
3. McBride MP, Wojick KB, Georoff TA, Kimbro J, Garner MM, Wang X, et al. Ophidiomyces ophiodiicola dermatitis in eight free-ranging timber rattlesnakes (Crotalus horridus) from Massachusetts. J Zoo Wildlife Med. 2015;46(1):86–94.