Fact Sheets



Snake Fungal Disease (SFD) is caused by the fungus Ophidiomyces ophiodiicolaan. This emerging disease is affecting wild snake species in eastern North America, including the northern water snake (Nerodia sipedon), eastern racer (Coluber constrictor), rat snake (Pantherophis obsoletus species complex), timber rattlesnake (Crotalus horridus), massasauga (Sistrurus catenatus), pygmy rattlesnake (Sistrurus miliarius), and milk snake (Lampropeltis triangulum). First noted in 2006, the disease varies in severity but has been associated with significant morbidity and mortality in some cases. In 2015, the Canadian Wildlife Health Cooperative (CWHC) confirmed SFD in Canada for the first time in an eastern foxsnake (Pantherophis vulpinus) in southwestern Ontario. As of July 6 2016 the CWHC has confirmed the disease in three eastern foxsnakes from Ontario. We do not know how widespread the fungus is in Ontario or if it occurs in other provinces. This is cause for concern in Ontario, where ten of our seventeen snake species, including the eastern foxsnake, are already provincially listed as species at risk.

Clinical signs of SFD can be severe and can include skin ulcers, invasion of deep muscle tissue and bone and, in rare cases, has been noted to invade the lungs and liver. However, the most consistent signs of the disease are scabs or crusty scales, subcutaneous nodules,  abnormal molting, white opaque cloudiness of the eyes that is not associated with molting, or localized thickening or crusting of the skin. In many cases affected snakes exhibit relatively mild signs similar to ‘hibernation sores’.


National Wildlife Health Centre's Snake Fungal Disease Information

Northeast Partners in Amphibian and Reptile Conservation