2007 pet food recalls
Beginning in March 2007, there was a widespread recall of many brands of cat and dog foods due to contamination with melamine and cyanuric acid.
Initially, the recalls were associated with the consumption of mostly wet pet foods made with wheat gluten from a single Chinese company.
In the following weeks, several other companies that had received the contaminated wheat gluten also voluntarily recalled dozens of pet food brands.
Reports that cyanuric acid may be an independently and potentially widely used adulterant in China have heightened concerns for both pet and human health.
Menu Foods acknowledged receiving the first complaints of sick pets on 20 February 2007, and initiated the recall following unexpected deaths after a regularly scheduled internal "taste test".
Below is an overview of affected brands, as provided by the FDA and the companies: The American Veterinary Medical Association (AVMA) maintains a combined list of all recalled pet food varieties.
[30][31][3] The U.S. Food and Drug Administration has received reports of approximately 8500 animal deaths, including at least 1950 cats and 2200 dogs who have died after eating contaminated food, but have only confirmed 14 cases, in part because there is no centralized government database of animal sickness or death in the United States as there are with humans (such as the Centers for Disease Control).
Dr. Barbara Powers, AAVLD president and director of the Colorado State University Veterinary Diagnostic Laboratory, said the survey probably found only a percentage of the actual cases.
Suspicions at that time focused on lead poisoning though Gu Junhua, a chief engineer from China's "national feedstuff quality check centre under the Ministry of Agriculture", was reported as saying: "But at present, he said it was difficult to draw any conclusions because the country has not drafted any food safety criteria for pets in terms of the quality and quantity of each element of the ingredients."
[39] Pet owners were advised to monitor their animals for the following signs of possible kidney failure that may be associated with the unknown toxicant: loss of appetite, lethargy, depression, vomiting, diarrhea, sudden changes in water consumption, and changes in the frequency or amount of urination.
[40][41] Ultrasounds of animals who have eaten the contaminated food in most cases show cortical echogenicity, perirenal fluid and pyelectasia.
[42] One of the largest veterinary hospital chains in the U.S., Banfield, has released statistics on the recent rates of pet kidney failure.
"[48] Aminopterin was widely described in news reports as a "rat poison", though that assertion may be based upon a hypothetical use listed in the 1951 patent application and not upon the actual use of the chemical.
"[51] Sometime in mid-March, an "unnamed pet food company" reported to Cornell they had discovered an industrial chemical used in plastics manufacture, melamine, in internal testing of wheat gluten samples.
[56] Despite the presence of the industrial chemical in both the food and in the animals, the FDA has made it clear they are still in the middle of an extensive investigation, and "not yet fully certain that melamine is the causative agent.
"[32] Prior animal studies have shown ingestion of melamine may lead to kidney stones, cancer or reproductive damage.
[2] Even at the highest observed concentrations found in wheat gluten, the melamine exposure is much smaller than the rat and mouse doses for which effects were seen.
"[32] However, Richard Goldstein of the Cornell University College of Veterinary Medicine has stated that "There appears to be other things in there, other than melamine, but identifying what they are is a long process.
(It was previously known that melamine and cyanuric acid can form networks of hydrogen bonds, creating a tile-like planar structure through molecular self-assembly.
[72] On 8 May 2007, the International Herald Tribune reported three Chinese chemical makers have said animal feed producers often purchase, or seek to purchase, the chemical, cyanuric acid, from their factories to blend into animal feed to give the false appearance of a higher level of protein, suggesting another potentially dangerous way that melamine and cyanuric acid might combine in protein products.
[4] A toxicology study conducted at the University of California, Davis School of Veterinary Medicine after the recalls concluded the combination of melamine and cyanuric acid in diet does lead to acute kidney injury in cats.
[73][74] Wilson Rumbeiha, an associate professor in MSU's Diagnostic Center for Population and Animal Health, commenting on results from a survey commissioned by the American Association of Veterinary Laboratory Diagnosticians and designed and implemented by MSU toxicologists which was also presented at the AAVLD's October 2007 meeting, said: "Unfortunately, these [melamine cyanurate] crystals don’t dissolve easily.
[78] The several waves of recalls, many issued late on Friday evenings possibly to avoid media coverage, and the events have caused distrust in some consumers.
On 20 March 2007 after the death of her cat, a woman in Chicago, Illinois sued Menu Foods for negligence in delaying the recall.
[84] By 5 April 2007 the 20 March Chicago lawsuit expanded to federal class-action status, with over 200 plaintiffs seeking punitive damages for emotional distress.
Kidney failure in the animals was linked to foods manufactured in Thailand by Mars, Inc. Veterinarians in Asia initially blamed the 2004 problems on fungal toxins, but pathology tests conducted in 2007 found melamine and cyanuric acid present in renal tissue from both outbreaks.
