How Vampire Bats Might Just Be the Next Big Threat to US Deer Herds

In the event that the news cycle hasn’t done enough to get your blood boiling lately, this one featuring some blood-sucking immigrants from the south should do the trick. In addition to dealing with exploding tick populations, a new scientific perspective published earlier this month is sounding the alarm against the threat of vampire bats who are expanding their range north and could have their sights set on infecting US deer herds.

While still hypothetical at this point, the paper, aptly titled “Emerging risks at the vampire bat–prion interface,” goes on to state that these adorable little flying syringes from Latin America are expanding their range northward thanks to slightly warmer winters. Given the fact that chronic wasting disease has already reached southern states like Texas and New Mexico, this  seemingly inevitable invasion could serve to create a dangerous new pathway for the deadly disease.

CWD is already chewing through cervid populations across 36 states with hard-hit areas seeing upwards of 25-40% prevalence in some herds. With current studies documenting measurable population declines in both whitetails and mule deer, layering on flying blood banks that feed on large mammals and share regurgitated meals at communal dinner parties now has the attention of biologists and wildlife managers alike.

Vampire bats, which are native to Latin America, are highly adaptable blood feeders that have a taste for livestock, wildlife and even the occasional human. Once back in their colony, they are known to share regurgitated meals through social grooming and feeding behaviors, leading to the core warning of the 2026 paper.

Given that prions (the misfolded proteins that cause CWD) circulate at low levels in the blood of infected cervids, even before obvious symptoms appear, a vampire bat feeding on a CWD-positive deer could ingest prions that survive digestion. Through bites or shared blood meals, the bat could then transmit those prions to other healthy deer or cervids, opening the door for bats to become competent vectors (or worse, if passage through a bat creates some spicy new prion strain). 

"This is a speculative concern, but it turns into a nightmare if it's real," stated Brent Race, DVM, a scientist at the National Institutes of Health's Rocky Mountain Laboratories. "Their opinion that bats may become a vector for CWD, or even worse, that bats may enhance the host range of CWD, warrants further study."

Researchers are already under the impression that southern deer herds are sitting ducks. Peter Larsen, co-director of the Minnesota Center for Prion Research and Outreach and co-author of the paper, estimates a roughly 70% chance that vampire bats in northern Mexico are already feeding on CWD-positive cervids. Having been bitten by a vampire bat himself on a 2022 research trip, he describes the potential bat–prion interface as “a national security issue” for wildlife.

Despite the harsh warning, no lab has fed bats CWD prions and watched the horror show unfold in an effort to prove transmission—yet. But the overlap is real, the trends are real (warmer winters, bats are moving, CWD is expanding), and the downside risk is catastrophic for anyone who likes seeing healthy deer herds or eating venison without playing prion roulette.

For now researchers recommend enhanced surveillance in overlap zones (southern U.S. and northern Mexico), ecological studies of bat feeding habits on cervids, cross-border monitoring (Mexico currently has limited CWD surveillance), and some good old-fashioned lab work.

Wildlife agencies and researchers are paying close attention, Hunters and outdoor enthusiasts should be too.