Wild Hogs Threaten Pork Industry

Feral pigs cause billions of dollars in damages and could help spread diseases to the nation's swine herd.

Numbers of wild pigs have swelled across the southern half of the U.S. since 1982 and have gradually crept into northern states. (Progressive Farmer image by USDA APHIS)

Few animals are as destructive as wild pigs. They root and wallow, causing extensive damage to fields and riverbanks. Wild pigs in the U.S. cause more than $2.5 billion in damages and control costs each year, according to USDA's National Wildlife Research Center. They also carry dozens of diseases and parasites that are communicable to people, pets and wildlife. Wild pigs have the potential to reintroduce diseases, such as pseudorabies and swine brucellosis, that have been eradicated in U.S. livestock to domestic swine herds.

It sounds like a recipe for disaster. For the nation's pork producers, that recipe has an additional dangerous ingredient: If a foreign animal disease like African swine fever (ASF) ever entered the wild pig population, the prospect of keeping it out of commercial herds would be next to nil. The virus would devastate the country's pork industry and endanger export markets worth more than $6 billion per year, according to the National Pork Board.

ASF does not affect humans, but the virus is highly contagious, and mortality can be as high as 100%. If the disease became prevalent in wild pig populations, it would be extremely difficult to eradicate.

Many experts feel it's not a matter of if but when ASF will permeate the nation's swine herd. The virus has been found in several European countries, and its steady, seemingly unstoppable spread across China since August 2018 is startling. As a result, producers and veterinarians feel the U.S. wild pig population needs to be controlled sooner rather than later.

"If [ASF] got into the wild pig population, it would be a disaster," says Scott Dee, a veterinarian with Pipestone Veterinary Services, in Pipestone, Minnesota. "I don't even like to have the conversation about what we'd do if it got in, because by that point, we've already lost the war."


At more than 6 million animals nationwide, the country's wild pig population is expanding and spreading due to natural population growth, illegal movement by humans and escapes from both commercial high-fence wild pig hunting and domestic swine production operations. Just as alarming is the fact that nearly 37% of pork operations are located in regions where wild pigs are common.

"If you're going to design a good species that can adapt and get established, feral swine would fit that thing," Dale Nolte, USDA national feral swine program manager, told CNBC in 2018. "They're very smart, they've very adaptable, and because of that, they damage almost all sectors."

John J. "Jack" Mayer has been conducting research on wild pigs for more than four decades and on three continents.He is a research scientist and manager at the Savannah River National Laboratory, in Aiken, South Carolina.

During most of the 20th century, wild pigs were consistently present in 18 to 20 states, Mayer says. In this decade, wild pigs have been reported in as many as 48 states and established in 35.

"If these weren't destructive animals, and you wanted to look at their potential as a big-game resource, that would be fine; but unfortunately, you also have one of the worst, most destructive, invasive species in that same animal," he adds. "It's a real Jekyll and Hyde situation -- if it were as simple as one or the other, it would be fine; but it's not. When you talk about wild pigs, people either typically love them or hate them."


"Modern swine confinement buildings have been quite successful in minimizing exposure of domestic hogs to wild hogs," says Alejandro Ramirez, with the Center for Food Security and Public Health. "Having a perimeter fence can also be helpful in preventing wildlife coming too close to your facilities. However, when feral swine do come in contact with commercial swine, producers should call their veterinarian, who can contact USDA APHIS [Animal and Plant Health Inspection Service] Wildlife Services."

Although no control measure has been found to be foolproof for controlling wild pigs, APHIS recommends the potential aids of fencing, harassment, trapping, snares, ground shooting or aerial gunning. However, wild pigs are smart and will often just move to another area.

Research is being conducted on oral contraception and toxicants, but to date, there isn't a registered product for use in controlling wild pig populations. Mayer hopes products will be available soon.


USDA APHIS recommends additional precautions to prevent interactions with your pigs if feral swine are found in your area. Livestock producers should store feed in barns and/or prevent wild pigs from accessing feed and water sources used by domestic swine. Producers also should avoid direct contact between wild pigs and domestic swine by maintaining fences and keeping pigs confined, especially at night.

Prior to beginning any control program, check federal, state, and local laws and regulations regarding hunting, use of firearms and traps, snares, etc.


In 2014, Congress appropriated $20 million to APHIS "for the creation of a collaborative, national feral swine damage management program." The agency reportedly is spending approximately $30 million per year on its efforts to control feral pigs and could be getting more with the new farm bill if the money is appropriated.

In one pilot program in New Mexico, feral swine have successfully been removed from5.3 million acres of land.

"We aim to eliminate feral swine from two states every three to five years and stabilize feral swine damage within 10 years," says Edward Avalos, former undersecretary for USDA Marketing and Regulatory Programs.

Mayer says the program has declared success in Idaho, Iowa, Maine and New York. The goal is to eradicate wild pigs from the northern tier states, where wild pig populations aren't as widespread or as dense as in the South.

The ultimate solution will be "a tough nut to crack," he admits. "There are people who like wild pigs and don't want to control the numbers. If they're surrounded by people who want to get rid of them, you're still going to have that pocket that will continue to generate wild pigs. If you can't get something that's 100% across the landscape, you're not going to solve this problem."

For more information and help in your area, contact USDA, APHIS, Wildlife Services at 866-487-3297, or use the Wildlife Services' program directory at www.aphis.usda.gov/aphis/ourfocus/wildlifedamage/sa_program_overview/ct_contact_us to contact your local program or connect with your local Extension agency, wildlife agency or other professionals in your area.


Past Issues