A four-year University of Georgia study has found that a combination of fungal, parasitic, and bacterial infections is hammering wild snake populations across the southeastern United States, and pygmy rattlesnakes are taking the worst of it. More than one in three pygmy rattlesnakes tested positive for a dangerous fungus, and researchers warn the findings carry real consequences for species already under environmental stress.
The research team examined more than 500 snakes spanning 29 species collected from Georgia, Florida, and South Carolina. They tested each animal for seven pathogens known to cause skin, gastrointestinal, and respiratory diseases. The results were grim: more than 40 percent of the snakes tested positive for multiple pathogens, and salmonella turned up in more than half of all animals studied.
But it was the fungus Ophidiomyces ophidiicola, the agent behind what scientists call snake fungal disease, that drew the sharpest concern. The fungus hit pygmy rattlesnakes especially hard. Twelve of 34 rattlesnakes tested positive, the New York Post reported, a rate far above the broader sample. Snakes infected with the fungus showed skin lesions, facial deformities, severe weight loss, and emaciation. Some lost up to a quarter of their body mass in a single month.
The study's corresponding author, Corinna Hazelrig, a doctoral graduate of the UGA College of Veterinary Medicine and the Southeastern Cooperative Wildlife Disease Study, said the real danger lies not just in any single pathogen but in what happens when infections stack up.
"Most snakes carrying salmonella appeared completely healthy, but the snakes with Ophidiomyces ophidiicola and the lung parasite were more likely to be emaciated and show visible clinical abnormalities."
Hazelrig added bluntly: "Co-infections further contributed to increased prevalence of disease."
That lung parasite, Raillietiella orientalis, commonly called snake lungworm, showed up exclusively in Florida snakes. The fungus, meanwhile, was more prevalent among Georgia populations. The geographic split suggests different regions face different disease pressures, complicating any single conservation strategy.
Wildlife diseases crossing species lines are not limited to snakes. Parasites and pathogens circulating in wild animal populations can carry broader ecological consequences, and sometimes public-health implications, that extend well beyond the species first affected.
The research also broke new ground by identifying Mycoplasma spp. in free-ranging snakes for the first time. That discovery expands the known range of bacterial threats facing wild reptile populations and underscores how much remains unknown about the diseases moving through these animals.
Hazelrig described the challenge in straightforward terms, as FOX Weather reported:
"A snake can carry a pathogen and still appear completely healthy. What matters is understanding what pushes infection into something deadly."
That distinction matters. A snake can harbor salmonella and show no outward signs of illness. But add a fungal infection or a parasitic lung infestation, and the animal's defenses buckle. The study found that co-infected snakes were far more likely to display visible disease, a pattern that suggests environmental stress may be the trigger that tips a manageable infection into a fatal one.
Hazelrig put it this way: "Any group or regional population of snakes is likely to be already under some level of stress, so they are primed for that fungus or bacteria to take advantage of them and become a full-blown infection."
The timing of the study's findings coincides with reports that a persistent western heat streak is pushing wildlife, including snakes, into closer contact with human communities. A warm spring led to snakes emerging from dormancy earlier than usual, and Dr. Ole Alcumbrac, Director of Wildlife Health Services, joined FOX Weather Meteorologist Bob Van Dillen to discuss the trend.
Record heat events have been stacking up across the central United States, and wildlife biologists note that prolonged heat can compound the environmental stressors that weaken animal immune systems and drive species into unfamiliar territory.
The broader ecological picture is not encouraging. Dr. Nicole Nemeth, the study's senior author and head of UGA's Southern Cooperative Wildlife Disease Study's research and diagnostic service, framed the stakes clearly:
"Snakes are a critical wildlife group due to their ecological importance as predators and prey. Understanding the prevalence and distribution of targeted pathogens is one piece of the puzzle toward understanding and better conserving snakes, as well as all the resources they and other wildlife need to survive."
That ecological role is easy to overlook. Snakes control rodent populations, serve as prey for raptors and larger predators, and occupy a link in the food chain whose removal would ripple outward. Officials have warned that the more these pathogens affect reptile populations, the more likely other animal species face downstream consequences.
Snake fungal disease itself is not new. The fungus Ophidiomyces ophidiicola has been identified in many snake species since its discovery roughly 20 years ago. But the UGA study's scale, 500-plus animals, 29 species, three states, four years, offers a more detailed picture of how widespread and overlapping these infections have become.
Dr. Corinna Mishin, identified in separate reporting by the New York Post, described the fungus and the lungworm parasite as "the most important infectious agents in free-ranging snakes in the south-eastern US." She also noted that "increased risks of ophidiomycosis were strongly associated with coinfections in free-ranging native snakes", reinforcing the study's central finding that layered infections are the real threat.
Researchers said better understanding of these pathogens could help conservation efforts for roughly one in five reptile species currently facing extinction worldwide. That is not a marginal number. It represents a significant share of global reptile biodiversity, and the southeastern United States, with its dense snake populations and warm climate, sits at the center of the problem.
The pattern of wildlife-linked diseases surfacing with increasing frequency extends beyond reptiles. From hantavirus outbreaks tied to rodent populations to invasive species reshaping ecosystems, the pressure on native wildlife keeps mounting.
Meanwhile, invasive species from abroad continue to spread across the country, adding yet another layer of ecological disruption that stresses native animal populations already weakened by disease.
The UGA study does not prescribe specific conservation actions, and several questions remain unanswered. The full identities of all seven pathogens tested were not detailed in available reporting. The specific conservation steps that might follow from the findings are unclear. And the study's exact publication date has not been confirmed.
What the data does show is that southeastern snake populations are carrying a heavy disease burden, that co-infections dramatically worsen outcomes, and that pygmy rattlesnakes are absorbing a disproportionate share of the damage. The geographic variation, fungus concentrated in Georgia, lungworm confined to Florida, suggests that effective responses will need to be tailored, not one-size-fits-all.
Conservation is not a word that belongs exclusively to the political left. Stewardship of the land and its wildlife has deep roots in the American conservative tradition, from Teddy Roosevelt's national parks to the hunters and ranchers who fund more wildlife management than any federal grant program. When disease threatens to collapse a species that keeps rodent populations in check and feeds the raptors overhead, that is not an abstract concern. It is a practical one.
Nature does not wait for a policy debate. The pathogens are already in the field, and the snakes are already losing weight.
