A female feral swine in Wheeler County recently tested positive for a contagious disease called pseudorabies that can harm livestock and several wildlife species.

The disease is common among feral swine across the country, but it is the first recorded case in Oregon. The U.S. Department of Agriculture Wildlife Services started surveying the state for the disease in 2007.

“This is a disease that coexists with feral swine populations in the U.S.,” said Ryan Scholz, an Oregon Department of Agriculture district veterinarian. “Oregon was somewhat of an anomaly that we had not had the disease.”

Officials suspect the disease is isolated to the lone swine, but they are investigating to determine if it has spread.

Pseudorabies does not affect humans, but can be fatal to farm animals and wildlife. It mainly infects pigs and causes neurologic, respiratory and reproductive disorders. It is a virus in the herpes family that resembles rabies and spreads through reproduction or nose-to-nose contact.

“These kinds of things can happen, and they can carry diseases that are concerning,” Scholz said. “There is more work to be done.”

The threat of the disease is a reminder of why officials are trying to eliminate the feral swine population in Oregon.

A decade ago, the population in Oregon grew to more than 3,000. They were spotted in Central Oregon from Madras to Shaniko and open terrain along the California border.

The pigs are considered one of the most dangerous invasive species in the state because they cause damage to agricultural crops and fish and wildlife habitat. They can also carry up to 40 diseases.

Through aerial hunting from helicopters and corral trapping, the population has been reduced to less than 200.

The remaining few are mostly roaming in the vast wilderness of Wheeler County, an agricultural county of fewer than 2,000 residents.

Every swine that is killed is tested for diseases.

Rick Boatner, invasive species wildlife integrity coordinator for the Oregon Department of Fish and Wildlife, said the state program to eliminate the feral swine has succeeded in Central Oregon, where the population from Madras to Shaniko has been nearly eradicated.

“There might be a few still around, but we haven’t had any reports in quite a few years,” Boatner said.

In 2009, the Oregon Legislature passed a law requiring landowners to notify the Oregon Department of Fish and Wildlife within 10 days if they see feral swine on their land.

Feral swine spread through Oregon from people bringing in exotic European and Russian boars for private hunts. Many of the boars escaped and mated with domestic pigs, Boatner said.

Feral swine can start breeding as early as 6 months old, and produce at least two litters per year with up to 12 in a litter. They grow up to nearly 300 pounds.

As omnivores, they eat almost anything in their paths, from small birds to roots in farmlands.

Michelle Dennehy, an ODFW spokeswoman, said the agency does not expect Oregon’s wildlife to be affected by the pseudorabies found in the feral swine.

Several species are susceptible to the disease, including raccoons, bears, deer, red fox, coyote, skunk, badgers, opossums, cottontails and muskrats. But there has never been an outbreak of the disease in Oregon wildlife, Dennehy said.

Wildlife officials hope that doesn’t change.

“We don’t want feral pigs in Oregon, and this is one of the reasons why,” Dennehy said. “There is definitely a risk for disease as shown here.”

For Scholz, he doesn’t believe the first case of pseudorabies in Oregon is cause for panic.

Instead, it is a motivation for farmers to protect their hogs and keep them away from feral swine. The commercial hog industry in the United States has been free of the disease since 2004.

“We want to remind everyone the disease out there and we do need to take those extra steps,” Scholz said.