Detection before treatment. Every time. And verification before documentation. Every time. It starts with the dog. It lives with the handler. Every time.
This post is a departure from our usual tone. Most of our bat content is about appreciating a genuinely beneficial, misunderstood animal. This one is about a disease that has already killed millions of them, has been confirmed in South Carolina since 2013, and has pushed at least one of our state’s bat species toward local disappearance in the exact caves where SCDNR has been counting them for over a decade. It matters, and it’s worth understanding clearly.
What Is White-Nose Syndrome?
White-nose syndrome (WNS) is a fungal disease that attacks hibernating bats, caused by Pseudogymnoascus destructans (Pd) — a cold-loving fungus that thrives specifically in the cold, humid conditions found in caves and mines where bats spend the winter. It was first documented near Albany, New York, during the winter of 2006–07. According to the U.S. Geological Survey’s 2025 science strategy report, WNS has since been confirmed in 40 U.S. states and 9 Canadian provinces, and of the 47 bat species native to the U.S., Alaska, Hawaii, and Canada, 12 have been affected — including three endangered species and one proposed for endangered status. Millions of bats have died.
How It Actually Kills Bats: Questions & Answers
Q: Why does it only affect bats during hibernation? A: Because that’s the only time bats are vulnerable to it. During hibernation, a bat’s body temperature drops to nearly match the cold cave air — often just 2 to 10°C — and its immune system becomes suppressed, which is exactly the narrow window this cold-adapted fungus needs to establish an infection on the skin of the nose, ears, and wings.
Q: How does a skin fungus actually kill a bat? A: Indirectly, but effectively. A 9-year peer-reviewed study tracking little brown bats found the fungus causes roughly a 60% reduction in how long bats stay in each hibernation torpor bout, forcing them to arouse far more often than normal through the winter. Every arousal burns stored fat that’s supposed to last until spring, and infected bats were found to have no depot fat reserves left by March — well before insects return and flying is worth the energy cost. Separately, the fungus damages the wing membrane itself, disrupting circulation and normal skin function and promoting dehydration, which compounds the problem.
Q: How deadly is it, really? A: Among the deadliest wildlife diseases on record. The same peer-reviewed study documented hibernation mortality rates of 75 to 98% across four affected species — the little brown bat, northern long-eared bat, Indiana bat, and tri-colored bat — in the first several years after the fungus arrived at a hibernation site. Some previously common species have been reduced by more than 90% across large parts of their range.
Q: Where did this fungus come from? A: The leading evidence points to Europe or Asia, where the same fungus is present in bat populations but does not cause mass die-offs — those bats appear to have co-evolved some tolerance to it over a much longer shared history. North American bat species, encountering it for the first time in the last two decades, had no such resistance built up.
Q: Is this a risk to people or pets? A: No. White-nose syndrome only affects bats — it is not known to infect humans, pets, or any other animals. The precautions around decontaminating clothing and gear after visiting caves exist to avoid accidentally carrying fungal spores to a new site and infecting more bats, not because of any health risk to people.
White-Nose Syndrome in South Carolina
This isn’t a distant problem. Per SCDNR, white-nose syndrome was first confirmed in South Carolina in March 2013 at Table Rock State Park in Pickens County, and the fungus has since been detected in at least nine additional counties. The impact on our tri-colored bat population has been severe: SCDNR reports declines of up to 97% at major Upstate hibernation sites since the fungus arrived, with one major site losing 91% of its population in just three years — dropping from hundreds of bats to roughly 30.
There’s a genuine glimmer of hope in that same data, though: small numbers of banded tri-colored bats have been documented returning to that site in subsequent years, suggesting at least some individuals may be surviving exposure or developing resistance. SCDNR has also noted that South Carolina’s comparatively warmer, shorter winters may give our bats a somewhat better survival outlook than the 90-100% mortality rates seen in harder-hit Northeastern states — though it’s far too early to call that a solved problem.
What’s Being Done, and How You Can Help
- Monitoring and testing. SCDNR biologists test hibernating bat colonies every winter (typically February and March, when symptoms are most detectable), sending samples to the National Wildlife Health Center and the Southeastern Cooperative Wildlife Disease Study for diagnosis.
- Decontamination protocols. Anyone entering caves or mines — researchers, cavers, and rock climbers alike — is asked to follow USFWS decontamination guidelines to avoid unintentionally transporting fungal spores between sites on clothing, gear, or boots.
- Vaccine and treatment research. Per USGS’s current science strategy, developing and optimizing a WNS vaccine and reducing environmental fungal levels are active, funded research priorities, though no cure or field-ready treatment exists yet.
- Citizen science. SCDNR’s Bat Watch program lets South Carolina residents help by counting bats at known roosts, providing population data that’s genuinely difficult for researchers to collect alone. If you’re aware of a hibernating colony on your property, SCDNR wants to hear from you.
- Supporting healthy roosts. While white-nose syndrome is specifically a winter hibernation disease, giving bats a clean, viable summer roosting option away from your home — like the bat house build we’ve covered separately — supports overall population resilience at a time when these species can’t afford additional pressure.
The CK9PS Bottom Line
We spend most of our bat content making the case for why these animals deserve a little more appreciation and a little less fear. White-nose syndrome is the other side of that coin — a real, documented, ongoing threat to the same bats doing free pest control over Aiken County every summer night. Understanding it doesn’t require panic. It requires the same thing everything else on this blog does: correct information, taken seriously, before deciding what to do about it.
Detection before treatment. Every time. And verification before documentation. Every time. It starts with the dog. It lives with the handler. Every time.
Know of a hibernating bat colony on your property, or found bats behaving unusually in winter? Contact Coastal K9 & Pest Solutions at 803-226-3155 or ck9ps.com — and consider reporting it to SCDNR as well.
Sources
- U.S. Geological Survey — “U.S. Geological Survey science strategy to address white-nose syndrome and bat health in 2025-2029”
- U.S. Fish and Wildlife Service — “Preventing and treating white-nose syndrome”
- Cornell Wildlife Health Lab — “White-Nose Syndrome” fact sheet
- Peer-reviewed: “The evolution of a bat population with white-nose syndrome (WNS) reveals a shift from an epizootic to an enzootic phase” — 9-year torpor/mortality study on Myotis lucifugus (PMC)
- Peer-reviewed: “Nutritional Capability of and Substrate Suitability for Pseudogymnoascus destructans” (PMC)
- South Carolina Department of Natural Resources — “Bats and White-nose Syndrome (WNS)”; South Carolina White-nose Syndrome Response Plan (2020)
SCDNR news releases (2016, 2018, 2020) — South Carolina-specific tri-colored bat decline statistics via Post and Courier / The Sumter Item / WIS-TV