As hunting season gets underway, the USDA is encouraging outdoors enthusiasts to keep a vigilant eye out for wild pigs. A complex and destructive invasive threat, wild swine not only heighten the risk of introducing African swine fever (ASF) into domestic herds, but they are also known to harbor dozens of pathogens—including the infectious prions responsible for Chronic Wasting Disease (CWD).
For hunters, livestock producers and wildlife agencies alike, containing this invasive species is no longer just about population control; it is an urgent race for biological defense.
The Looming Livestock Threat: African Swine Fever
Although ASF is currently not present in the U.S., the highly contagious, deadly viral disease spreads rapidly and affects domestic and feral swine alike. A single confirmed case could prompt sweeping export bans and eradicate regional herds, risking multi-billion-dollar losses to the economy and threatening the livelihoods of more than 610,000 Americans who work across the pork supply chain.
“You have a unique opportunity to help protect our pigs,” USDA says, noting that outdoor recreationists and hunters are often the first to spot emerging disease patterns in the wild.
A Producer’s Warning
For Jimmy Kinder, an Oklahoma cattle producer, wild hogs concern him greatly.
“I’m not an expert,” Kinder says. “I don’t hunt hogs for sport. We shoot wild hogs on site and have used government traps and helicopters. I’m not an ASF expert, but I do worry about feral hogs as a vector for disease.”
In his part of the country, many hunters look forward to killing wild hogs for personal consumption. On social media, Kinder warned them to know the facts first.
“Before you bring one home to the freezer, please know that wild hogs carry more than 30 diseases and nearly 40 parasites, including brucellosis, leptospirosis, pseudorabies, trichinellosis, toxoplasmosis, salmonella, E. coli, swine influenza and hepatitis E, all of which can threaten humans, livestock, pets and wildlife,” he wrote.
The Intersection of Deer and Wild Pigs
Beyond traditional livestock and zoonotic diseases, emerging research reveals that feral swine are playing a troubling role in America’s deer management crisis.
A study published in the journal Emerging Infectious Diseases detected CWD prions in the tissues of wild hogs. While there are no recorded cases of hogs developing clinical signs of the fatal neurological condition that devastates cervids (deer, elk and moose), researchers emphasize that swine can still spread the infectious material.
“Results from this study showed that wild pigs are exposed to cervid prions, although the pigs seem to display some resistance to infection via natural exposure,” the study authors explain. “Future studies should address the susceptibility of this invasive animal species to the multiple prion strains circulating in the environment. Nonetheless, identification of CWD prions in wild pig tissues indicated the potential for pigs to move prions across the landscape, which may, in turn, influence the epidemiology and geographic spread of CWD.”
Because wild hogs are opportunistic scavengers that readily feed on deer carcasses, they can ingest prions and shed them in new locations. This unmonitored movement—compounded by gaps in state transport regulations and operations where deer and pigs share high-fenced enclosures—creates a new, hidden pathway for CWD dissemination.
How Hunters Can Spot Disease in the Field
“Seeing signs of disease while hunting could be the first sign of ASF in the U.S.,” USDA emphasizes. When heading afield this season, hunters should keep three vital monitoring practices in mind:
1. Know the Area: Feral swine were first introduced to the Americas in the 1500s as a food source, followed by the release of Eurasian wild boars in the 1900s for sport hunting. Today’s feral swine are a prolific hybrid of escaped domestic breeds and wild boars. Hunters should review USDA-APHIS
Feral Swine Distribution Maps before hunting in new territories.
2. Avoid Sick or Dead Animals: If a feral pig looks sick or is found dead, do not handle or transport it. Be alert for classic signs of acute swine disease, including high fever, lethargy, red or blotchy skin lesions, diarrhea, vomiting, labored breathing or sudden unexplained death.
3. Report Sightings Immediately: Report sick or dead feral swine without delay via the “Squeal on Pigs” mobile app or by calling APHIS Wildlife Services at 1-866-4-USDA-WS. Landowners and hunters can also notify their local state wildlife agency or university Extension office.
6 Steps to Stop Disease Spread
Biosecurity afield means taking every practical measure to prevent the transfer of pathogens to domestic herds and uncontaminated game habitats. USDA recommends six core field practices:
Step 1: Dispose of waste properly.
Do not leave food scraps, carcass remains or garbage where wildlife can access them.
Step 2: Practice safe field dressing.
Field dress harvested game promptly and always wear disposable nitrile or rubber gloves when handling blood, viscera and raw tissues. Wash hands thoroughly with soap and water afterward.
Step 3: Transport meat in leak-proof containers.
Ensure harvested game is sealed securely to prevent blood or fluids from leaking out of truck beds onto roadways and private ground.
Step 4: Clean and change gear.
Before leaving hunting grounds or entering domestic livestock premises, change out of hunting clothing and footwear. Launder garments in hot water and disinfect boot soles.
Step 5: Sanitize vehicles and equipment.
Thoroughly wash trucks, trailers, UTVs, knives and processing gear. Ensure all blood and tissue residue is removed from skull caps and capes before transport.
Step 6: Avoid contact with domestic swine.
While ASF does not infect humans, people can easily transport the virus on contaminated boots, clothing, and truck tires. After hunting, avoid visiting commercial pig farms, backyard pens, auction barns or petting zoos.
