The United States Department of Agriculture reports that there are more than 5 million feral pigs roaming in the country, and Arkansas and Oklahoma are among the states with the highest population.
State Veterinarian Dr. Rod Hall of the Oklahoma Department of Agriculture, Food and Forestry told Ozarks Farm & Neighbor that animal health officials in his state are concerned about diseases that can be carried by the wild swine, primarily pseudorabies and swine brucellosis, which have both been eradicated from domestic livestock.
Hall explained that officials are testing feral hogs that are trapped and/or killed in the state and are finding brucellosis in about 10 percent of those tested.
“Once they are infected with brucellosis, they are continually spreading that disease, and it can be spread to humans,” he said. “We’ve had reports from other states from when people haven’t take enough precautions when they clean feral swine that they plan to eat.”
Hall added that brucellosis can be passed on to other livestock and that there have been cases of dogs in Oklahoma being infected with the disease. Cattle are also prone to infection, but there is currently no testing for the disease.
“We haven’t had any confirmed cases or evidence of where there was brucellosis transferred from feral swine to cattle, but Texas has,” he said. “The issue is that we have been free of brucellosis for so long that there isn’t any testing at the livestock markets. The good thing is that cattle are kind of the dead-end host because it doesn’t spread from cow to cow.”
There have been cases where brucellosis has been transferred from the feral population to domestic hog herds. Hall said in one case, which involved a producer’s group of show pigs, the entire herd had to be “depopulated.”
In addition to brucellosis, pseudorabies is another concern for animal health officials. Hall said that about 30 percent of the feral hogs tested were positive for the disease.
“That doesn’t mean that they are all spreading it, but they have it,” he said. “Pseudorabies is actually a disease that animals can develop an immunity to, so when we test those, we are actually testing for immunity to the disease. The percentage of wild hogs actually spreading the disease is much lower, but there have been reports of dogs dying from pseudorabies. It does not affect people, which is a good thing, and it could infect cattle. Again, our big concern is if it gets into the commercial swine industry and their ability to ship those swine to international markets because about 30 percent of our swine products go international.”
Unfortunately, vaccinations are not given to livestock to ward against pseudorabies or brucellosis.
“The best prevention we have is to prevent contact between domestic livestock and feral hogs and I know that is easier said than done,” Hall said.
Hall added that because the vast majority of commercially offered pork comes from confinement operations, it is very unlikely that feral hogs will come in contact with a large number of domestic pig herds.
