Tony Caver, the state's veterinarian, said the state is working with the US Department of Agriculture to prevent the hogs "from getting into the food chain."

The melamine was found in food produced by Diamond Pet Food in Columbia, said Sam Davis, feed control official for the state Department of Agriculture. The feed is part of the waste product of making dog food, he said, adding that hogs are omnivores.

Only one pork producer in the state uses feed from Diamond, he said. The farm, which was not identified, was put under restriction -- a voluntary measure to keep hogs on site during the investigation, he said.

Asked how consumers can be assured that contaminated hogs had not already entered the food chain, Caver said that he assumes that pork produced in South Carolina can travel to market in other states as well as being sold here. He said, however, that all the hogs he knows of in this case have been kept out of the food chain. Urine samples at the farm revealed low levels of melamine in the hogs, Caver said. But just what that means is unclear because the feed tested negative. FDA officials said last week that since contamination wasn't found throughout the feed, it's possible that one sample could test positive while another tested negative.

Source: GreenvilleOnline.com