Vampire bat invasion: A threat to the U.S. livestock industry?

Halloween is long gone, but it’s still spooky season. That is, if you live anywhere near the U.S.-Mexico border with vampire bats inching their way farther north.

These creepy creatures are the only mammals adapted to survive on blood alone, and according to a new study published in Ecography, this bloodthirsty species has gradually expanded into the northern hemisphere as the climate has changed over the past century,

“We expect an invasion of vampire bats to US soil between five and 20 years in the future,” Luis Escobar, an assistant professor of wildlife conservation at Virginia Tech, reported. Other climate models have also predicted their move into the southern parts of Texas and Florida, with some reports estimating the species will be on U.S. soil any time in the next five to 20 years.

While researchers believe that rabies, a common disease to the species, helps control bat numbers, it’s a problem when it crosses into domestic species and humans. The U.S. Department of Agriculture estimates that the bats cost Mexican ranchers over $46.7 million annually when livestock are infected by rabies. It’s estimated that about 2 percent of unvaccinated cattle die from rabies in year in Mexico, while up to 20 percent die in certain areas of the country.

Using sharp front teeth, the bats make incisions in the skin of their victim and use their latch to eat a few teaspoons of blood with their tongues. A local anesthetic in their spit allows the bats to drink blood without being detected by prey for a half hour at a time, while a blood thinner keeps their victim’s blood blowing.

In preparation for a spillover event, U.S. officials released a National Rabies Management Program report in September. The program implemented surveillance for the disease in cattle in 2016, and has been educating farmers and ranchers in the U.S. and Mexico on the signs of vampire bat bites.

“This bat species causes a lot of concern in agriculture due to its ability to transmit diseases, injure livestock, and cause infections. Rabies is the most obvious issue because of livestock welfare and potential to infect humans,” Gary Joiner, a spokesperson for the Texas Farm Bureau, told Wired.

Although rare in humans, rabies is a serious, fatal viral disease affecting mammals. According to the Centers for Disease Control, the symptoms of rabies in humans and livestock are similar, affecting the central nervous system and ultimately resulting in death.

Rabies can be prevented through vaccinating animals on a regular basis. A rabies calculator is available on the USDA website to estimate the coft effectiveness of vaccinating livestock for rabies.