In 1539, Spanish explorer Hernando de Soto brought thirteen pigs ashore in what is now Florida. Within three years, that small herd had exploded to 700 animals. Some escaped. Some were released. Five centuries later, their descendants—mixed with European wild boar and escaped domestic pigs—number 6.9 million across at least 35 U.S. states, costing American agriculture $1.6 billion annually.
The financial toll goes beyond trampled crops and rooted-up pastures. Feral hogs have become mobile disease reservoirs, capable of carrying pathogens that threaten not just wildlife but the entire domestic livestock industry.
The Hybrid Threat
Modern feral hogs aren't purely wild animals. They're genetic mashups of domestic pigs, European wild boar introduced for hunting, and every possible cross between the two. This ancestry matters because domestic pig genetics give them exceptional reproductive rates—populations can double in four months—while wild boar genetics provide the survival instincts and physical hardiness to thrive in diverse environments.
This combination creates an animal uniquely suited to spreading disease. They range widely, contact both wildlife and domestic livestock, root through soil and vegetation, and concentrate near water sources that other animals depend on. In Texas, 73% of farms report feral hog presence. In Louisiana, it's 65%. These aren't occasional visitors. They're permanent residents with expanding territories.
Three Diseases Worth Losing Sleep Over
African Swine Fever hasn't reached U.S. soil yet, but "yet" does most of the work in that sentence. The virus jumped from sub-Saharan warthogs to Eurasian pig populations in 2007. By 2021, it had reached the Dominican Republic and Haiti. It spreads through bodily fluids, contaminated feed, infected carcasses, and even on clothing and boots. Most infected pigs die. There's no vaccine. There's no treatment.
If ASF enters the U.S. feral hog population, eradication becomes nearly impossible. Warthogs in Africa carry the virus without symptoms, serving as permanent reservoirs. Feral hogs could do the same in North America, creating a persistent threat to the $23 billion U.S. pork industry. Unlike domestic pigs in biosecure facilities, you can't quarantine wild animals scattered across millions of acres.
Classical Swine Fever presents a similar nightmare in a different package. This pestivirus survives in refrigerated pork for months and in frozen pork for years. It spreads through direct contact between pigs or through infected pork products. Once established in a feral population, it becomes a permanent threat to nearby farms. The virus doesn't respect fence lines.
New World Screwworm adds a visceral dimension to the problem. Female flies lay eggs in open wounds—any open wound, on any warm-blooded animal. The larvae burrow into living flesh using hooked mouthparts, feeding for about a week before dropping to the ground to pupate. Feral hogs, constantly fighting and injuring themselves while rooting, become both hosts and dispersal mechanisms. The flies they carry don't distinguish between wild hogs and cattle, between livestock and pets, or between animals and humans.
The Contact Zone Problem
The real danger lies in the interface between wild and domestic populations. Feral hogs don't stay in forests. They raid agricultural land for crops, water, and the easy calories that come from spilled feed and grain. A hog carrying a pathogen can contaminate water sources, rub against fences, root through soil near barns, or directly contact domestic pigs in outdoor facilities.
Cattle operations reported $61 million in losses from feral hogs in 2025, goat operations $10 million, sheep $7.4 million. Some of that comes from direct predation—yes, feral hogs kill livestock, particularly young animals. But disease transmission and the costs of preventing it account for a substantial portion. Farmers pay for veterinary surveillance, enhanced biosecurity, repairs to compromised barriers, and the constant vigilance required when a disease vector lives in your back forty.
Crop damage adds another layer of economic pain. Sorghum fields in counties with feral hog activity lost 6.4% of production, corn lost 4%, peanuts 2.8%. That's $203 million in direct crop losses, but it understates the problem. Those figures don't capture the cost of control efforts, the value of lost soil health from rooting damage, or the opportunity costs when farmers switch to less profitable crops that hogs find less appealing.
Missouri's Lonely Success Story
One state has reversed the trend. Missouri reported just 3% of producers with feral hog presence in recent surveys, and over half reported declining populations. The difference? A coordinated, aggressive elimination effort that treated feral hogs as an invasive species to be eradicated rather than a wildlife population to be managed.
The approach worked because it was comprehensive and sustained. Neighboring states, meanwhile, continue to see explosive growth. In Louisiana, 87% of producers reported growing feral hog populations over the past three years. In Alabama, 86% saw increases. The pattern is clear: half measures fail. Feral hogs reproduce too quickly for anything less than systematic removal to make a difference.
Missouri's success came through the Feral Swine Eradication and Control Pilot Project, which demonstrated measurable results. The program is currently unfunded. That decision may haunt American agriculture for decades.
Biosecurity on a Continental Scale
Preventing disease transmission from feral hogs to domestic livestock requires thinking at two different scales simultaneously. On individual farms, it means physical barriers, strict protocols about clothing and equipment, monitored water sources, and rapid response to any breach. At the landscape level, it demands population control, surveillance systems for early pathogen detection, and coordinated action across property boundaries and state lines.
The National Swine Health Strategy exists largely on paper. It outlines monitoring systems for emerging foreign pathogens, rapid response protocols, and the infrastructure needed for early detection. Implementation remains incomplete. We're watching diseases move geographically closer—ASF in the Caribbean, screwworm periodically reappearing in southern border states—while the animal populations that could spread them continue to expand.
The stamping-out protocol for disease outbreaks in feral hog populations is straightforward in theory: early detection, movement control, proper carcass disposal, intensive cleaning and disinfection. In practice, that means finding infected animals in millions of acres of varied terrain, preventing movement by populations with no respect for boundaries, and disposing of potentially thousands of carcasses in remote locations. Even the best-case scenarios involve years of effort and hundreds of millions in costs.
The $1.6 Billion Question
American agriculture is waiting for a crisis that hasn't happened yet. African Swine Fever hasn't jumped the water gap. Classical Swine Fever hasn't established itself in U.S. feral populations. Screwworm remains mostly a southern border concern. The $1.6 billion in current annual losses comes primarily from crop damage, predation, and prevention costs.
When—not if—a major swine disease establishes itself in North America's 6.9 million feral hogs, those losses will seem quaint. The pork industry will face international trade restrictions. Cattle and other livestock operations will contend with expanded disease risks. Small farms without resources for intensive biosecurity will be forced to make impossible choices.
Missouri proved that feral hog populations can be controlled. The pilot project that achieved those results no longer has funding. That gap between demonstrated solutions and implemented policy defines the current moment. We know what works. We know what's coming. And we're waiting.