What Is Snake Fungal Disease? Understanding the Potentially Devastating Fungus That Could Be a Global Threat

A timber rattlesnake, a species that Snake Fungal Disease almost wiped out. Dan Proud / Flickr

Biologists recently discovered that a fungal disease in snakes has the potential to infect any type of snake. If the disease spreads, it could pose a global threat to ecosystems.

But what is this disease, and how does it work?

Scientists identified the fungus that causes Snake Fungal Disease (SFD), Ophidiomyces ophiodiicola, in 2015. However, the fungus has been present in North America much longer than that, and was known to be potentially devastating to snakes in 2006, according to the BBC. In fact, it was so dangerous that it cut the population of timber rattlesnakes in half, from 40 to only 20.

Researchers at the Cornell Wildlife Health Lab have tested the infection on a variety of snakes. They observed that, as early as 12 days after infection, a snake can show symptoms of the fungus. It can infect the eyes, nose, mouth, throat and lungs, and cause blindness and difficulty breathing and eating. It even can cause pneumonia.

As the fungus spreads over the body, it usually stays right under the scales, causing strange swellings of fungus. However, sometimes it can penetrate the animal's body and cause a systemic fungal infection.

While antifungal treatment exists, that treatment only has been known to work in some species of snakes. For untreated snakes, there is a 40 percent mortality rate, according to Cornell. While snakes sometimes cure themselves by shedding their skin, shedding only takes place periodically and sometimes they die before getting the chance.

While most of the infections take place in Europe and the United States, the snakes affected in the wild and in the lab are so diverse that scientists believe that all snakes could get this disease.

We still don't know as much as we would like to about SFD. For example, how does it spread? "It could be in the environment already, it could be transmitted by humans or even captive animals," Frank Burbrink, associate curator at the American Museum of Natural History, told Newsweek. "But we know definitely that it spreads from one snake to another when they touch."

If Snake Fungal Disease were spread without control, it would be devastating to the world's ecosystems and the people who depend on them.

This is a northern water snake (Nerodia sipedon) with crusty and thickened scales overlaying raised blisters as a result of a fungal skin infection. © USGS National Wildlife Health Center/D.E. Green

"Snakes have a massive service for human beings, they eat rodents, they serve as food for other animals," Burbrink said. "This could be pretty devastating, and they're important in the food web as mid-level predators. We can't afford to lose them as a whole."