The Six-Million-Animal Problem No Hunter Can Afford to Ignore
Every fall, millions of American men head into the woods after deer, elk, turkey, and waterfowl. The ritual is as old as the country itself. But in 2025, those same fields and creek bottoms are increasingly shared with an uninvited guest — one that tears up the landscape, outcompetes native wildlife, threatens the entire domestic pork industry, and carries a staggering biological payload. Feral swine have been reported in at least 35 states, and their population is now estimated at over six million animals. That number is not static. Feral hogs are known to have reproductive rates that allow populations to double in just four months, meaning their path of destruction expands rather rapidly. The scale of the invasion is almost incomprehensible, and it has brought with it a suite of disease risks that reach far beyond the hog itself — threatening domestic livestock, deer herds, hunting dogs, and the men who pull the trigger.
Feral hogs continue to be a scourge on U.S. agriculture, causing an estimated $1.6 billion per year in damage, which includes damage to property and crops as well as predation and diseases inflicted on domestic livestock. But money is only part of the equation. Wild swine not only heighten the risk of introducing African swine fever into domestic herds, but they are also known to harbor dozens of pathogens — including the infectious prions responsible for Chronic Wasting Disease. For a hunter, that means the animal charging through your food plot or getting rolled by a well-placed shot from a blind is not just a pest. It is a walking biohazard, and ignoring that reality has consequences.
African Swine Fever: The Disease That Could Reshape American Agriculture
Hunters play a very important role in protecting the American swine herd from African swine fever — a highly contagious and deadly viral disease that spreads rapidly and affects domestic and feral swine alike. The stakes could not be higher. It has been estimated that an ASF outbreak in the U.S. would cost the economy nearly $80 billion, due to loss of exports and reduced industry revenue, but could also affect the crop sector due to decreased feed demand. That is not a rounding error. That is a catastrophic economic event that would ripple from feedlots in Iowa to grocery shelves in every city in the country.
African swine fever is a highly contagious viral disease that exclusively affects wild boar and domestic pigs and is considered harmless to humans. That distinction matters for the man in the woods — he is not going to catch ASF himself — but his silence or inaction in the face of a sick animal could set off a chain of events with national consequences. Clinically, the disease manifests in extreme cases through high fever, weakness, bleeding and very high mortality rates in domestic and wild boar. The virus spreads through exposure to bodily fluids from an infected pig. It can also be transmitted via contaminated feed, garbage feeding, and contact with infected carcasses in the environment.
How Close Is ASF to American Soil?
Feral swine are known carriers of foreign animal diseases, including African Swine Fever, a virus with no known treatment or vaccine. The United States has been fortunate: ASF has yet to be detected in domestic or wild pigs within its borders. But fortune is a thin line of defense. In 2007, the disease was accidentally introduced to the Eurasian continent and has been spreading through domestic swine operations and populations of Eurasian wild boar across Europe and Asia. The trajectory has been relentless. In June of 2021, the disease was identified near the United States in the Dominican Republic, and in September it was also identified in Haiti. The disease now sits in America's backyard, separated from the mainland by a stretch of Caribbean water and whatever vigilance customs and biosecurity measures can muster.
The extensive feral hog population across much of the country would further complicate containment efforts if ASF were to arrive. Unlike a domestic operation, where sick animals can be quarantined and tested, feral hogs move freely across state lines, across farm fences, and through the same creek drainages and timber ridges that hunters travel every season. Seeing signs of disease during a hunting trip may be the first sighting of ASF in the United States. Though it is not a threat to humans, if ASF were to come to this country, it would interrupt pork production and could cause severe job loss for anyone whose livelihood involves pigs.
The USDA has been direct in its messaging to the hunting community. "Seeing signs of disease while hunting could be the first sign of ASF in the U.S.," the USDA emphasizes. USDA APHIS conducts feral swine monitoring for diseases to help safeguard pork production in the U.S., with more than 6,000 samples taken annually to test for diseases of concern. That surveillance network, however, can only cover so much ground. The rest falls on the boots on the ground — hunters.
The Pathogen Inventory: More Than 30 Diseases in a Single Animal
African swine fever, despite its dramatic potential, is not the only disease threat that feral hogs carry into the American hunting landscape. The roster of pathogens found in wild pigs reads like an infectious disease textbook. "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." That warning came from Oklahoma cattle producer Jimmy Kinder, who has watched wild hogs encroach on his operation and understands better than most what that kind of biological exposure means for everyone downstream.
Swine Brucellosis: The Silent Threat to Every Man Who Field Dresses a Hog
Feral hogs can carry and transmit several diseases to wildlife and humans. Three diseases that cause the most concern are swine brucellosis, pseudorabies, and tularemia, although feral hogs harbor other diseases as well. Of these, swine brucellosis poses the most direct and personal danger to hunters. Swine brucellosis causes flu-like symptoms and is incurable. Humans can contract it through an open wound, by splashing fluids in their eyes while field-dressing, or simply by consuming infected meat. That last detail deserves emphasis: the route of transmission does not require a dramatic encounter. A nick from a bone while breaking down a carcass, a splash to the eye without protective eyewear, or improperly cooked wild pork can each be sufficient.
Brucella suis is a Gram-negative coccobacilli and facultative intracellular pathogen that can cause zoonotic infections in pigs and other animals, including humans and wild boars, leading to abortions and infertility. In humans, the disease typically produces flu-like symptoms including intermittent fever, headaches, muscle and joint soreness, and weakness. Though few humans die of infection, the disease is often chronic and debilitating. The chronicity is what makes it particularly brutal — men who contract brucellosis may suffer for years with recurring symptoms that physicians unfamiliar with the disease can easily misdiagnose.
"Every year in Texas, we seem to have one or two cases where hunters or individuals that are trapping and then slaughtering wild pigs for consumption contract swine brucellosis," says one wildlife extension specialist. Texas, which holds the largest feral hog population in the country — estimated at 2.9 million animals in 2024 alone — reports these cases with near-clockwork regularity. Hunters and people working with feral pig carcasses are most at risk. Because feral pigs can transmit the disease to domestic animals, including cattle and dogs, people who have close contact with those animals are also at risk. Hunting dogs are most at risk because they have contact with infected animals, including eating their meat.
Hog hunters are commonly infected by bare skin contact when butchering feral swine carcasses. The fix is straightforward but widely ignored in the field: individuals should take precautions to protect themselves from infection when handling wild pigs, including either live animals or carcasses. Surgical gloves should always be worn and probably offer sufficient protection for the hunter who handles a pig or two every year.
Pseudorabies: Deadly to Your Dogs, Catastrophic for Domestic Pork
Pseudorabies is a viral disease that causes abortions, stillbirths, and respiratory problems in pigs and death in piglets. Commercial swine production herds in the U.S. have been PRV-free since early 2003. Infections continue to occur in feral swine and in domestic swine that come in contact with feral swine. That clean bill of health in commercial operations took decades to achieve and enormous financial investment — all of it at risk from a single contact point between a domestic herd and a feral pig.
For hunters who run dogs on hogs — a deeply rooted tradition across the South — pseudorabies represents a genuine hazard. Dogs exposed to feral hogs are at risk for pseudorabies. Dogs should not be fed raw feral hog meat. The disease is not a threat to humans, but it is always fatal in dogs. A man can lose his best deer dog to a disease he never knew the hog he killed was carrying. That is a cost that never shows up in the $1.6 billion annual damage figure.
Tularemia and Leptospirosis: Two More Reasons to Wear Gloves
Researchers at Texas Tech University tested 130 feral hogs and found that 50% of tested hogs in Crosby County and 15% in Bell and Coryell counties showed past exposure or were currently infected with tularemia. Tularemia — also known as rabbit fever — is not exclusive to rabbits or rodents. Feral hogs carry it too, and it is transmissible to humans through direct contact with infected tissue, contaminated water, and insect vectors. When humans contract tularemia, flu-like symptoms occur along with swollen lymph nodes. Severe cases can result in pneumonia, blood infections, or meningitis.
Leptospirosis rounds out the major bacterial threats. Leptospirosis, which is caused by a bacterium, has been found in feral swine populations. If left untreated in people, it can cause kidney damage, meningitis, liver failure, respiratory distress, and death, according to the CDC. Feral hog fecal material can transmit additional diseases, which can pose a problem when supplemental feed for livestock or wildlife is placed on the ground, increasing the chances of fecal contamination. That is a direct concern for any hunter running a deer feeder or food plot on the same ground where hogs are active — which, increasingly, describes nearly every property in the South and lower Midwest.
The CWD Connection: Feral Hogs and America's Deer Hunting Crisis
If the direct human health risks are not enough to change how hunters think about wild pigs, consider what these animals may be doing to the deer herds that hunters care most deeply about. Beyond traditional livestock and zoonotic diseases, emerging research reveals that feral swine are playing a troubling role in America's deer management crisis. Chronic Wasting Disease is already one of the most consequential threats ever to face North American deer, elk, and moose populations. The discovery that feral hogs may be entangled in its spread adds a layer of complexity that wildlife managers are only beginning to fully understand.
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, researchers emphasize that swine can still spread the infectious material. The mechanism is disturbingly plausible: 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.
For hunters, this means that the feral hog raiding a food plot at 2 a.m. is not merely eating the corn meant for deer. In a CWD-positive area, it may also be carrying prions from a carcass it fed on days earlier into a new drainage where CWD has never been detected. The geography of the disease could shift in ways that surveillance programs — built around the movement of deer, not pigs — are not designed to track.
The Scale of the Invasion: 35 States and Counting
The range expansion over the last few decades is due to a variety of factors including adaptability to a variety of climates and conditions, translocation by humans, and a lack of natural predators. The translocation piece is not accidental or random — it has often been deliberate. Feral hogs were moved to new areas by people who wanted them there for hunting, a shortsighted practice that wildlife agencies in multiple states have worked to prohibit but have struggled to fully eliminate. The result is a population map that now covers most of the South, stretches up through the Midwest, and has footholds in states that had no feral pig populations a generation ago.
As the number of feral pigs increases, they encroach into human habitats in search of feed, thus amplifying the risk of zoonotic disease transmission. Feral pig hunters, farmers, slaughterhouse workers, and animal health workers are at increased risk of contracting zoonotic diseases associated with feral pigs. The hunting community, in particular, sits at the intersection of all of these risk categories. A hunter who shoots, field-dresses, transports, and processes a feral hog has taken on every exposure opportunity that the animal represents.
Around six million feral swine run wild in at least 35 U.S. states, where they can grow more than five feet long and weigh more than 500 pounds. They are adaptable creatures, capable of thriving in nearly any environment. Female feral pigs can reproduce at just eight months old, which means every population control effort is fighting a biological clock that never stops ticking. So far, trying to kill feral swine outright has not worked. Officials in the Great Smoky Mountains have removed over 15,000 feral swine since trapping and hunting efforts began, but the population remains relatively unchanged.
Hunters as the First Line of Defense
The USDA's framing of hunters as biosecurity assets is not flattery — it is operational reality. Animal health surveillance is the key to detecting animal diseases early so we can respond quickly and prevent the spread. Federal and state agencies cannot be everywhere. They do not have the boots, the land access, or the situational awareness that hunters collectively possess. A man sitting in a box blind at dawn, glassing a field or a creek bottom, sees things that no government trapper ever will.
"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. That framing transforms the hunter from a sport participant into something closer to a field epidemiologist — not through any dramatic action, but through simple observation and reporting. A dead hog with unusual skin lesions. A group of pigs behaving lethargically. An animal that stumbles rather than bolts. These are the early signals that could alert disease investigators before an outbreak becomes a crisis.
What to Do — and What Not to Do — in the Field
If a feral pig looks sick or is found dead, do not handle or transport it. That basic instruction runs counter to the instinct of many hunters, particularly those who want a closer look or who are hoping to salvage meat. Resist it. The downside of handling a sick or dead hog far outweighs any potential benefit. To limit exposure to potential diseases, hunters should not process feral hogs that exhibit any signs of illness.
For hogs that appear healthy and are taken legally, protective equipment is non-negotiable during processing. When handling hogs or raw meat, wear impermeable gloves; refrain from eating, drinking, or using tobacco products; avoid direct contact with blood, other body fluids, feces, and raw meat; wash and disinfect any surface that comes in contact with raw meat or blood; and wash hands frequently. These are not overcautious guidelines written by bureaucrats who have never skinned an animal. They reflect the documented transmission routes of diseases that have put real hunters in the hospital.
USDA APHIS conducts feral swine monitoring for diseases to help safeguard pork production in the U.S. More than 6,000 samples are taken annually to test for diseases of concern. This monitoring effort not only keeps domestic swine safe but also keeps humans safe from diseases that can infect people. Hunters who observe sick animals and report them through their state wildlife agency or directly to USDA APHIS are contributing data to that surveillance network — data that cannot be collected any other way.
The Producer's Perspective: Where the Hunting World Meets the Farming World
Jimmy Kinder, an Oklahoma cattle producer, represents the voice of agricultural America when it comes to feral hogs. For Kinder, wild hogs are a constant concern. "I'm not an ASF expert, but I do worry about feral hogs as a vector for disease," he says. His worry is well-founded and echoed across livestock country from Texas to Tennessee. The connection between the recreational hunting of feral pigs and the biosecurity of domestic herds is not theoretical — it is direct. Every animal left in the field, every carcass hauled to a new county, and every hunter who fails to report unusual signs is a variable in a biosecurity equation that livestock producers have no control over.
In general, feral hogs have the potential to contract and transmit all of the diseases of domestic swine. Because of this, feral hogs have the potential to function as a disease reservoir that can impact nearby domestic swine herds. Additional diseases that are contracted by feral hogs can also infect other wild and domestic mammals as well as man. Such disease impacts are the most significant and potentially most expensive type of damage that feral hogs can cause to the agricultural industry in the United States today.
Feral swine can harbor and infect domestic swine with diseases such as African Swine Fever, foot-and-mouth disease, pseudorabies, swine brucellosis, and others. The fence line between a feral population rooting through bottomland timber and a commercial swine operation is often the only barrier that exists. And feral hogs, which tear through hog wire without hesitation, do not respect that barrier.
The Global Context: What Europe's Experience Tells Us
The United States does not need to guess what an ASF outbreak amplified by a large wild boar population looks like. Europe has been living that reality for years. In Europe, ASF has been spreading for years, with focal points in Eastern Europe and recurring new outbreaks in various regions. In Estonia alone, multiple outbreaks in commercial farms were confirmed with over 17,000 pigs culled in a single reporting period. The economic damage has been severe, and the presence of wild boar populations has made containment exponentially more difficult than in regions where the disease existed only in domestic herds.
ASF causes massive economic damage because all animals in domestic pig populations are killed and far-reaching trade restrictions are imposed. It is precisely this economic pressure that is used to justify an increasingly severe tightening of hunting regimes on wild boar. In several European countries, wild boar hunting has been transformed from a leisure activity into a government-mandated control measure, with hunters required to submit carcasses for testing and operate under strict movement protocols. That model — hunters as active participants in disease surveillance — is exactly what the USDA is trying to build in the United States before an outbreak forces the issue.
A Race That Only Gets Harder
In 2014, recognizing the rising tide of damage, Congress funded the creation of a National Feral Swine Damage Management Program through APHIS. This program's mission is to safeguard not only agriculture and property, but also animal health and the safety of local communities. That program has made progress in some states, but the scale of the problem continues to outpace the response. Estimates place the feral swine population at over six million, with numbers climbing every year. Their adaptability to harsh and varied environments, combined with a lack of natural predators and human-assisted movement, has fueled this relentless invasion.
The spotlight is once again on feral hogs as the threat of the New World screwworm inches closer to the United States. It is possible that feral hogs can carry the parasite and deliver it to animals that mainly live outdoors, such as horses, cattle, and even pasture-raised swine. The addition of new parasitic threats to the existing disease portfolio makes the feral hog problem even more complex to manage — and even more urgent to take seriously.
For the hunter heading afield this fall, feral pigs are no longer just a bonus target or a nuisance to ignore. They are a biosecurity front line. The man who shoots a hog, handles it properly, reports anything unusual, and stays informed about the diseases these animals carry is not just protecting himself. He is protecting his dogs, his neighbors' livestock, the deer herd he has spent years managing, and a domestic pork industry that puts bacon on every breakfast table in America. That is a pretty substantial return on a pair of nitrile gloves and a phone call to the state wildlife agency.
