Humans at risk from tainted pet food'
Federal officials confirmed Thursday they are investigating whether pork products intended for humans are contaminated with the same industrial chemical that prompted a massive pet food recall and sickened cats and dogs nationwide.
Researchers also have identified three other contaminants in the urine and kidneys of animals sickened or killed after eating the recalled foods, including cyanuric acid, a chemical commonly used in pool chlorination, three researchers told the Pittsburgh Tribune-Review. Cyanuric acid is what most likely sickened pets, one researcher said.
Melamine previously was found in the recalled pet food and two ingredients -- wheat gluten and rice protein concentrate -- as well as in the urine, blood, kidneys and tissues of infected animals.
Researchers and U.S. Food and Drug Administration officials said since it was discovered in the pet food, wheat gluten and in animals' urine and kidneys, they did not believe it was what sickened the animals.
The Trib learned yesterday that melamine-contaminated feed was fed to hogs.The FDA, U.S. Department of Agriculture and the California Department of Food and Agriculture are investigating.
Some animals that are believed to have eaten the contaminated food were slaughtered and sold as food before authorities learned their feed had been contaminated, said Nancy Lungren, spokeswoman for the California agriculture department.
The state quarantined the farm Wednesday, she said.
Yesterday, the urine of some pigs at the 1,500-animal American Hog Farm in Ceres, Calif., tested positive for melamine, although all appeared healthy, Lungren said. About half a dozen pigs were put down and researchers at the University of California-Davis are testing their kidneys, tissues, blood and other body parts for melamine contamination, she said.
The contaminated feed was bought April 3 and 13 as salvage pet food from Diamond Pet Foods Inc., which received contaminated rice protein concentrate used in some recalled Natural Balance pet food, Lungren said.
Diamond Pet Foods made the dog and cat foods recalled this week by Natural Balance after melamine was found in an ingredient, rice protein concentrate.
Researchers isolated a spoke-like crystal in pet food, wheat gluten and in the urine, kidneys and tissues of infected animals. That crystal serves as a marker for determining what animals were sickened in the outbreak. About 30 percent of those crystals are made up of melamine, one investigator said, and researchers spent several weeks trying to identify what is in the remainder.
Researchers in at least three labs found cyanuric acid, amilorine and amiloride -- all by-products of melamine -- in the crystals of animals' urine, tissues and kidneys, according to Dr. Brent Hoff, a veterinarian and clinical toxicologist and pathologist, at the University of Guelph, in Ontario, Canada; Richard Goldstein, associate professor of medicine at Cornell University's College of Veterinary Medicine and a kidney specialist, and Dr. Thomas Mullaney, acting director of Michigan State University's Center for Population and Animal Health.
Michigan State's lab so far has found only the amilorine and amiloride, but Mullaney said he was aware of at least three other labs finding the cyanuric acid in the animals. The FDA asked labs involved in the pet food recall to test for the three chemicals.
All three are by-products of melamine, which researchers said they believe were formed as the animals metabolized the melamine.
Finding cyanuric acid is the more significant finding, Hoff, Goldstein and Mullaney said, although they are not yet certain how toxic it is to animals.
The Centers for Disease Control and Prevention's Web site said, "When ingested (by humans) in large amounts, the substance may have effects on the kidneys, resulting in tissue lesions."
Because cyanuric acid was used in pool chlorination, more scientific studies have been done on that chemical than on melamine, amilorine and amiloride, Goldstein said. However, tests in dogs and rats found it is safe, he said.
Hoff, Goldstein and Mullaney said amilorine and amiloride were found earlier this week in low concentrations.
The findings have not been announced yet, because officials overseeing the research are seeking confirmation from as many labs as possible, they said.
Researchers ruled out aminopterin -- used as rat poison in other countries -- which New York state officials previously announced was in the pet food.
The FDA said the contaminated wheat gluten and rice protein concentrate used in pet food in the United States and Canada and melamine-tainted corn gluten used in recalled pet food in South Africa have been traced to companies in China.
The Chinese government told the Trib and the FDA yesterday that the Xuzhou Anying Biologic Technology Development Co. Ltd., which the FDA said supplied the tainted wheat gluten, did not export any wheat gluten intended to be used in food.
The FDA has received more than 15,000 calls reporting sick or dead cats and dogs since the pet food recall began last month, but the agency has not confirmed those yet.
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