Wild hogs harbor disease

Published 9:29 pm Wednesday, May 10, 2017

JACKSON (AP) — Most everyone who has encountered wild hogs knows the non-native species is a problem. Feral swine destroy crops, root up food plots and out-compete deer and other native wildlife species for food. But pigs present another danger — leptospirosis.

“Leptospirosis is a bacterial infection,” said William McKinley, Mississippi Department of Wildlife, Fisheries, and Parks wildlife biologist. “It’s common in the environment.

“Multiple animals can get it including deer and humans. Wild hogs are a reservoir for it, meaning they are walking around shedding it everywhere. It is primarily passed through urine.”

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Not only are wild hogs shedding the disease, they seem to be doing a lot of it. MDWFP nuisance animal biologist Anthony Ballard said research done by the US Department of Agriculture indicates 61 percent of the wild hogs in Mississippi have been infected with the disease at some point in their lives.

And when the bacteria are shed, it lingers. According to the Centers for Disease Control and Prevention, leptospira can live outside a host for a matter of weeks or months, depending on conditions. If a water source is infected, it becomes more of a risk.

“We see outbreaks of it during flooding events,” Ballard said. “Anything that drinks that water, including humans, has the ability to contract that disease.

“It is definitely a concern. Wild hogs are such a reservoir for so many diseases. Hogs are hosts to about 30 types of bacterial and virulent diseases and 37 parasites. They can contract things and live with it that will kill other animals. They can carry on, do their thing and basically be unaffected.”

In deer, particularly young and unborn deer, that’s not the case.

“It can cause abortions and kill young deer,” McKinley said. “Young deer are most likely to be killed by it.

“Older deer can carry it. The older deer may not show symptoms.”

Although it’s possible that the levels of leptospirosis in Mississippi wild hogs could be negatively impacting deer density in some areas, there is no smoking gun. For now, it’s a suspicion and McKinley said he hopes to further investigate the significance of diseases being transmitted from wild hogs to deer.