Added 5:15pm: Hogs in 3 states have tested positive for melamine. (As reported on the CBS Evening News)
The U.S. Food and Drug Administration said on Tuesday that "thousands" of U.S. hogs might be affected by the agency's investigation of livestock feed contaminated with melamine.
"I don't have the numbers on that right now but it potentially affects thousands of hogs," Stephen Sundlof, director of the FDA's Center for Veterinary Medicine, told reporters. "Some of the hog operations were fairly sizable."
Livestock feed that may have been contaminated with ingredients imported from China was sent to hog farms in North and South Carolina, California, New York, Utah and "possibly" Ohio, he said.
N.C. hogs got food tainted with melamine (Note: this is in addition to ones in California that we heard about last week. )
Hogs at a western North Carolina farm have tested positive for melamine, the industrial chemical blamed for killing and sickening dogs and cats that ate it in their food.
North Carolina Department of Agriculture officials said that none of the hogs that ate the tainted food have entered the food chain for human consumption. The department has quarantined the farm, which has about 1,400 hogs, until it the U.S. Food and Drug Administration can advise what to do next.
The department declined to release the name of the farm. It said no other farms are believed to have been affected.
"The system worked and these animals were intercepted before they were allowed to leave the farm," said Mary Ann McBride, assistant state veterinarian for the department. "We want people to know the food is very much safe."
In California, officials have quarantined 1,500 animals at the American Hog Farm in Ceres, Calif., where hogs are also believed to have eaten tainted food.
North Carolina investigators are attempting to determine whether the melamine was absorbed into the meat of the pigs and whether it would eventually be safe to eat.
N.C. officials said the pigs' food came from a proccessing plant in South Carolina. That food contained a rice protein concentrate from San Francisco-based Wilbur-Ellis Co., one of three pet food makers that recalled products last week that were tainted with rice protein concentrate imported from China.