An aerial view is seen of a neighborhood that was flooded after Hurricane Matthew in Lumberton, North Carolina October 10, 2016.
© Reuters/Chris KeaneAn aerial view is seen of a neighborhood that was flooded after Hurricane Matthew in Lumberton, North Carolina October 10, 2016.
Millions of farm animals in North Carolina drowned in the floodwaters caused by Hurricane Matthew.

In addition to the massive amount of agricultural casualties, flooded farms in North Carolina — the state with the world's highest concentration of pork production — have also caused pools of hog feces to swell and spill into local waterways, officials said.

The animal death toll was highest among chicken farms, with roughly 5 million birds perishing in the rising waters, according to North Carolina environmental officials.

There was a "tremendous loss of life on the poultry side," said Donald van der Vaart, secretary of the North Carolina Department of Environmental Quality.

Last year North Carolina — home to poulry giants Tyson, Sanderson Farms, Inc., and Perdue Farms — produced about 823 million chickens for meat, according to the U.S. Department of Agriculture.

Agriculture is the state's largest economy, generating about $84 billion to the economy, according to the North Carolina Department of Agriculture and Consumer Services.

It's unclear how many pigs were killed in flooded farms but Rick Dove, an environmentalist for the Waterkeeper Alliance, said he saw thousands of floating carcasses, the Washington Post reported.

"There's a real problem here," Dove said, estimating that "tens of thousands of dead hogs" could turn up in the floodwaters.

Van der Vaart said that floodwater mixed with potentially toxic hog manure could eventually make its way into streams, rivers and the Atlantic Ocean. Hog manure contains antibiotic-resistant pathogenic bacteria, according to Mother Jones.

At least 17 people have died in North Carolina in the storm's aftermath. All but one has been vehicle-related. The other person died in a fire that was attributed to the storm.

With News Wire Services