Thousands of hogs and millions of chickens ate pet food now subject to a recall, but government agencies have found no evidence of harm to humans in association with meat from the animals.
The Department of Agriculture and the Food and Drug Administration stated that hogs in California, Illinois, Kansas, New York, North Carolina, South Carolina, and Utah ate some of the pet food in question. Chickens in more than one state ate byproducts of pet food containing adulterants. As of early May, the USDA and FDA continued to investigate additional sites.
A few hundred hogs and several million broiler chickens already had gone to market, but no recalls of pork or poultry products were issued. The USDA had begun approving meat from hogs and chickens that ate the pet food if their feed did not contain detectable concentrations of melamine.
The pet food included ingredients from China that the FDA has found to contain the adulterant melamine and compounds with structural similarities to melamine. The FDA and USDA are attempting to trace all shipments of ingredients containing melamine.
Feed contamination is a fairly uncommon occurrence, said Dr. Tom Burkgren, executive director of the American Association of Swine Veterinarians. He added that most pork producers feed a ration of corn and soybean meal to control their inputs and thus maintain nutritional balance and optimize growth. He said the practice of feeding hogs with food waste, which could range from salvage pet food to cookie crumbs, was more prevalent in the past.
Dr. Kenneth Petersen, assistant administrator for field operations with the USDA Food Safety and Inspection Service, said modern swine and poultry operations that do feed some pet food tend to include salvage or byproducts as a small percent of rations.
According to the USDA and FDA, the risk to human health from eating meat in this case is very low, largely because of the dilution of adulterants. The adulterants are in one ingredient in each pet food. The pet food is one part of hog feed or chicken feed. Pork and poultry are only part of the average American diet.