Snake fungal disease in North America: U.S. Geological Survey updates

Fact Sheet 2017-3064
By: , and 



Snake fungal disease (SFD) results from a skin infection that has been documented only in snakes. Historically, reports of snakes with skin infections of unknown origin have been sporadic. Recently, the number of reported cases of skin infections in snakes has increased substantially. This emerging infectious disease, confirmed in numerous species of snakes, is caused by the fungus Ophidiomyces ophiodiicola. As of August 2017, O. ophiodiicola has been detected in at least 23 States and one Canadian Province. However, researchers suspect that SFD may be more widely distributed than these documented cases suggest, because efforts to monitor the health of many snake populations are limited. Snake fungal disease may also be underreported in populations where it affects snakes infrequently or in species that develop less severe illness. Signs of SFD include crusted or ulcerated scales, nodules (that is, abnormal bumps) under the skin, and facial disfiguration that can be quite severe, leading to emaciation and death. Many snake populations are already in decline due to habitat loss and dwindling prey populations, and the recent emergence of SFD may accelerate this decline, causing certain species to disappear entirely from some locations.

Suggested Citation

Thompson, N.E., Lankau, E.W., and Rogall, G.M., 2018, Snake fungal disease in North America—U.S. Geological Survey updates: U.S. Geological Survey Fact Sheet 2017–3064, 4 p.,

ISSN: 2327-6932 (online)

ISSN: 2327-6916 (print)

Table of Contents

  • Host Range of Ophidiomyces ophiodiicola (as of January 2018)
  • U.S. Geological Survey Contributions to Understanding Snake Fungal Disease
  • References Cited
Publication type Report
Publication Subtype USGS Numbered Series
Title Snake fungal disease in North America: U.S. Geological Survey updates
Series title Fact Sheet
Series number 2017-3064
DOI 10.3133/fs20173064
Year Published 2018
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) National Wildlife Health Center
Description 4 p.
Online Only (Y/N) N
Additional Online Files (Y/N) N
Google Analytic Metrics Metrics page
Additional publication details