Animal and Plant Health Inspection Service

Program Aid No. 2174 FERAL SWINE:

An Overview of 

a Growing Problem

About Our Work

Wildlife Services, part of the U.S. Department 

of Agriculture’s (USDA) Animal and Plant Health 

Inspection Service (APHIS), is conducting a 

national program to manage the damage 

caused by invasive feral swine through the 

National Feral Swine Damage Management 

Program. Our main goal with this program is 

to protect agricultural and natural resources, 

property, animal health, and human health 

and safety by reducing feral swine damage in 

the United States and its territories. Through 

a coordinated national effort, we work closely 

with partners at the Federal, State, and local 

levels to address the extensive damage caused 

by feral swine populations.

How You Can Help

Wherever feral swine are, they become a 

problem, threatening livestock, agriculture, 

property, forests and other natural areas, native 

wildlife, and public health and safety.

• Report any feral swine sightings, signs, or 

damage to wildlife and agriculture officials in 

your State. This is especially important if you 

live in an area with very few or no feral swine.

• Don’t relocate feral swine to new areas or 

transport them to other States.

• Spread the word to discourage others from 

transporting and spreading feral swine to 

new areas.

INTERACTING WITH LIVESTOCK

ROOTING DAMAGE

Animal and Plant Health Inspection Service

Want To Learn More?

Call the USDA-APHIS Wildlife Services program in 

your State at 1-866-4-USDA-WS or go to www.

aphis.usda.gov/wildlife-damage/stopferalswine

to learn more about the problems caused by 

this invasive animal, as well as to seek advice and 

assistance in dealing with feral swine.

The U.S. Department of Agriculture is an equal

opportunity provider, employer, and lender.

Program Aid No. 2195a 

Revised May 2020
Property damage and destroyed 

vegetation from rooting or 

digging; can be extensive and 

cover several acres

Wallows (wide, shallow holes) in 

moist areas in warmer months

Rubbing marks on trees and fence 

or power line posts (often occur 

after wallowing, leaving behind 

mud, hair, and scent)

Tunnels and trails through 

thick vegetation

Feral swine “scat” (resembles 

dog feces and may contain acorns, 

grains, and animal hair, scales,

or feathers)

Tracks in the mud near springs, 

ponds, and streams

What Are Feral Swine?

Feral swine (also called wild pigs, Eurasian boar, 

or feral hogs) are a harmful and destructive 

invasive species. They are not native to North 

America. Early explorers and settlers first 

brought feral swine into the United States in 

the 1500s as a source of food. The number of 

feral swine grew further after that; they were 

introduced repeatedly in different areas of the 

country and also started crossbreeding with 

escaped domestic pigs. Today, approximately 

6 million feral swine can be found across more 

than 31 States.

What Do They 

Look Like?

Why Are They a Problem?

Feral swine cause major damage to property, agriculture (crops and livestock), native species and ecosystems, 

and cultural and historic resources. In fact, this invasive species costs the United States billions each year 

in damages and control costs. Feral swine also threaten the health of people, wildlife, pets, and other 

domestic animals. 

AGRICULTURE

Feral swine damage crops and destroy land 

with their feeding, rooting, trampling, and 

wallowing behaviors. They can spread diseases 

to livestock and even attack and kill them, 

mainly calves and lambs. Feral swine also 

degrade pasture grasses; eat, contaminate, 

and destroy livestock feed; and damage 

farm property, such as fences, water systems, 

irrigation ditches, troughs, and levees.

NATURAL RESOURCES

Feral swine behaviors, such as eating, rooting, 

compacting soil, and wallowing, all damage 

native plants. Feral swine also compete with 

native wildlife for food, eat invertebrates 

and other small animals, and destroy nests 

and consume eggs of reptiles and groundnesting birds. Because feral swine prefer wet 

environments, they can also compete with 

native wildlife for water during dry seasons.

HEALTH AND PUBLIC SAFETY

Feral swine can carry at least 30 diseases and 

nearly 40 types of parasites that may affect 

people, pets, livestock, and wildlife. They can 

also transmit foodborne illnesses, such as 

E. coli, toxoplasmosis, and trichinosis. 

Feral swine have been aggressive in some 

encounters with people and may also threaten 

pets. And, when in roadways or at airports, 

feral swine can cause car accidents and aircraft 

collisions, posing direct risks for public safety.

PROPERTY

Feral swine destroy landscaping, damage fences 

and other structures, and otherwise reduce the 

aesthetic value of private properties, public 

parks, and recreational areas. Because of their 

large size, collisions with vehicles and aircraft 

can result in costly property damage.

CULTURAL AND HISTORIC RESOURCES

Other resources affected by feral swine include 

national historic sites, tribal sacred sites and 

burial grounds, cemeteries, and archaeological 

sites and digs. Feral swine damage structures, 

destroy vegetation, and disturb soil and land. 

This can seriously degrade the significance and 

historic integrity of these sites.

Feral swine come in many different sizes 

and colors because of their extensive 

crossbreeding. Some look like pure Russian 

or Eurasian wild boars, while others look 

more like domestic pigs. Adults weigh from 

75 to 250 pounds on average, but can get 

twice as large as that. They generally have a 

thick coat of coarse, bristly hair. DAMAGED CORN FIELD

Signs of Feral Swine