Could Vampire Bats End Up Carrying Chronic Wasting Disease? One Researcher Thinks It's Worth Asking Now

Vampire bats are creeping north out of Mexico. Chronic wasting disease is creeping south out of the Rockies. A prion researcher wants everyone to start thinking about what happens if those two trend lines ever cross, before it becomes a real problem instead of a hypothetical one.

Two range maps are moving toward each other, and one disease researcher can't stop thinking about what happens if they meet. Vampire bats are expanding north out of South and Central America into Mexico. Chronic wasting disease, the always-fatal prion disease that's been chewing through deer and elk populations, keeps expanding its own footprint south and east. Neither trend is new. What is new is a University of Minnesota researcher publicly connecting the dots between them.

Peter Larsen, associate professor in the University of Minnesota's Department of Veterinary and Biomedical Sciences and co-director of the Minnesota Center for Prion Research and Outreach, has a personal reason for paying close attention to vampire bats. He was bitten by one while doing fieldwork in South America. That experience nudged him toward researching whether these bats could end up as an unexpected link in the CWD story, either by picking up prions themselves or by helping the disease find new hosts.

If we think this can never happen, and then it starts happening, we're already behind.

Wyoming Isn't the Worry. Texas Might Be.

Before anyone starts picturing vampire bats swooping through the Bighorns, Larsen is clear that Wyoming itself is very low on the risk list. Vampire bats are built for hot, humid climates, and he puts the odds of them ever reaching the state at very low. New Mexico within the next decade is a more realistic ceiling for their range.

The more interesting concern involves insect-eating bat species that already tolerate colder climates. Larsen's theory is that these bats could pick up CWD prions indirectly, through blood-engorged insects that fed on infected animals. Add in the possibility that CWD-positive white-tailed deer were exported from Texas ranches into Mexico, and you get a scenario where vampire bats south of the border could already be feeding on infected deer without anyone knowing it.

From there, the real worry isn't the bats spreading CWD directly to Wyoming wildlife. It's what happens if vampire bats moving into Texas start layering prion exposure on top of the rabies risk they're already known to carry into cattle herds.

The Science Says Slow Down, Not Panic

Every veterinary voice in this story pushes back hard on the idea that cattle are at any real risk right now. Wyoming State Veterinarian Hallie Hasel told Cowboy State Daily there's zero evidence of bovine spongiform encephalopathy, the cattle-specific prion disease known as mad cow disease, anywhere in Wyoming. She called the idea of CWD sickening Wyoming cattle not a concern in any way.

Former Montana state veterinarian Martin Zaluski offered the most useful framing for why that confidence exists. Prion diseases are highly species specific, he said, until they're not, and those exceptions are exceptionally rare. CWD has likely been circulating in deer and elk since the 1940s or 1950s without ever making the jump into cattle, despite decades of environmental overlap. If prions were going to move between deer and cattle through soil, water, or plants, the opportunity has already existed for a very long time.

So Why Bring This Up at All

Larsen's point isn't that vampire bats are about to become a CWD superspreader. It's that the profession has a track record of treating emerging threats as impossible right up until they aren't. He pointed to the recent New World screwworm outbreak in Texas cattle as a case study in something that caught people off guard when a little more early attention might have softened the landing.

He's also floating a bigger, more speculative concern in the background. CWD prions have become so widespread across such a large geographic area that Larsen wonders whether they could contribute to prion disease showing up in species where nobody's currently looking for it. He's flagged cases of animals presenting with rabies-like symptoms that tested negative for rabies, and he's asking out loud whether some of those could be missed prion disease. That's a hypothesis, not a finding, but it's the kind of question that tends to age well when someone asks it early.

Where This Leaves Practicing Vets

There is no documented case of a human getting sick from eating CWD-infected deer or elk meat, a track record that stands in real contrast to the human toll of mad cow disease in the 1980s and 90s. Nothing in this story changes current clinical guidance for cattle practices in Wyoming or anywhere else in CWD country.

What it does argue for is keeping an eye on the research rather than filing this under settled science. Larsen isn't asking anyone to sound an alarm. He's asking the field to keep studying a low-probability, high-consequence scenario before it has any chance of becoming a real one, which is a pretty reasonable ask for a disease that's already proven it doesn't respect the boundaries anyone expected it to stay inside.

Source: Mark Heinz, "Biologists Concerned Vampire Bats Could Transmit Chronic Wasting Disease To Cattle, Humans," Cowboy State Daily, August 8, 2026.