On April 24 and 27, 2007, Chenango Valley Pet Foods, a company that manufacturers product for SmartPak and Doctors Foster & Smith and SmartPak brands recalled products after melamine or melamine metabolites (including cyanuric acid hydrolase) were found in rice gluten, an ingredient used in some pet foods. The Food and Drug Administration (FDA) is investigating three chemical compounds associated with melamine production, including cyanuric acid hydrolase, said David Elder, director of the FDA’s office of enforcement and regulatory affairs.

Over the last month, several types of vegetable gluten (rice, wheat, and corn) imported from China have tested positive for melamine and melamine byproducts after pet owners reported illness and death in pets that consumed the food. Melamine, a chemical used in fertilizers and plastics, may have been added to the gluten by Chinese companies to boost protein levels, according to FDA officials. The compound is known to be moderately toxic, which is why veterinary toxicologists question whether melamine metabolites, which are created during melamine production and include cyanuric acid hydrolase, may be causing pet deaths.

In addition to affecting pet foods, tainted glutens have been identified in animal feed in eight states and could affect 6,000 hogs that have been quarantined or put “on hold,” said Kenneth Peterson, assistant administrator for field operations for the Food Safety and Inspection Service of the United States Department of Agriculture (USDA).
Petersen explained that none of those animals will receive a USDA mark of inspection, which is required for food to enter the food supply; Peterson also explained that farmers will be compensated with Section 32 funds to restore their purchasing power.

On April 26, 2007, government officials said that tracing contaminated feed within the human food chain is their priority and admitted that they may never determine the final number of pets killed or injured by the ingestion of contaminated pet foods.

“Our focus is on removing [the ingredients] from commerce,” said Daniel McChesney, DVM, director of the FDA’s Center for Veterinary Medicine surveillance and compliance office. “We have received many thousands of calls from consumers [pet owners] but we’re not sure if we’ll ever come up with a final number [of pets affected.] We’re not sure that we’ll ever get there.”

Expansion of the Recall
The issue began in March 2007, when Menu Foods recalled products from the market that had melamine or melamine metabolites. It was expanded April 18, 2007, to include rice protein concentrate (a type of gluten) imported from China. FDA officials said U.S. companies may have started receiving contaminated rice gluten shipments from China in July 2006, but they did not provide more details.

Rice gluten distributed by Wilbur-Ellis tested positive for melamine, a chemical used in fertilizer and plastic, which prompted Natural Balance Pet Food, Blue Buffalo, Royal Canin, SmartPak, and Doctors Foster & Smith to recall products within the last two weeks.

In South Africa, many pets died after eating pet foods containing melamine-laced corn gluten, but FDA officials say United States companies did not receive those shipments. Several companies have announced the fact that they source corn gluten from the United States. However, surveillance of imports now includes wheat, corn, and rice gluten, soy protein, rice bran, and corn meal, said Stephen Sundloff, DVM, PhD, director of the FDA’s Center for Veterinary Medicine.

Statistics from the FDA show that at least 16 pets died after eating tainted food, however, veterinary sources believe food contaminants could have caused hundreds of fatalities.

For regular updates, visit the Food and Drug Administration FDA and AAHA web sites. The FDA has agreed to do biweekly teleconferences for press members and AAHA will share news from those conferences through NEWStat  and the association web site.

In response to questions from concerned pet owners, veterinarians are tapping manufacturers for information about safe food recommendations. For example, Hill’s Pet Food Nutrition and some other companies have tested rice products and released statements about the safety of their food, said Claudia Kirk, DVM, PhD, a board-certified nutritionist who participated in a senate hearing on the FDA’s response to the recall.

Following a Rice Gluten Trail
Government officials are using the “Prior Notice Requirement” system to trace all of the contaminated rice and wheat gluten ingredients. It was introduced after the 2001 terrorist attacks as part of the Bioterrorism Act. “The investigation is open,” said Elder. “We will continue to follow the trail ‘til it ends.”

During a press conference on April 24, 2007, FDA officials said the United States may have received shipments of contaminated rice gluten since July 2006. They added that tainted wheat gluten was sent to at least 10 hog farms and perhaps one poultry farm in Missouri; they did not rule out that it may have affected chicken feed. Officials, however, do not believe that the contaminants have entered the commercial human food stream.

David Acheson, MD, chief medical officer for the FDA, said he hopes this incident will sensitize the industry and “raise awareness with manufacturers and processors about the importance of knowing all there is to know about their suppliers.”

Acheson introduced a new “food surveillance assignment” that will monitor a variety of imported ingredients for pet and human food, which he described as proactive. He said the FDA is only aware of two suppliers – Wilbur-Ellis and ChemNutra Inc. – that imported ingredients with melamine, but the government is casting a wide net to protect consumers and prevent future problems.

“We are simply asking the question, ‘could this have gone into other areas that we don’t know about,’” Acheson said. “It’s a smart public health move” to expand testing and surveillance, he added.

In addition to hundreds of pets that have reportedly gotten sick and died from eating contaminated foods, melamine has been detected in the urine of hogs at farms in North Carolina, California, and South Carolina. All of the hogs affected had ingested food that contained the gluten from China. Farms in New York, Utah, and perhaps Ohio have also been identified as possible recipients of contaminated feed, and animals have been quarantined in most of those locations, said FDA officials.

When asked whether the hogs would be tested or euthanized, Peterson said he expects that the animals will be destroyed.

Veterinary professionals and pet owners can find a complete list of recalled products online. Although the number of companies affected continues to increase, the recall has only affected one percent of the available foods, according to the Pet Food Institute. And while safe options for commercial pet foods exist, some people may decide to steer clear of vegetable glutens until all contaminated products have been identified, Kirk said.

Why is Melamine in Pet Food?
Despite the confusion surrounding the pet food recall, FDA officials were clear on one message: Melamine should not be in the food supply. It is not approved for use in fertilizers in the United States and it should never be in pet foods. “The headline is that [melamine] shouldn’t be there,” said Michael Rogers, director of the FDA’s field investigation.

When asked how it got into food, Stephen Sundloff, DVM, PhD, director of the FDA’s Center for Veterinary Medicine, said one theory is that Chinese companies may have added melamine to the gluten products as a way to inflate protein levels. “It’s still a theory, but it seems like a plausible one,” he said.

Tests used in the food supply to gauge protein levels of ingredients are sensitive to nitrogen, a gas found in melamine, Kirk explained. Any nitrogen compound identified by the “quick” test is assumed to be from a protein, she added. Labels that show “crude protein levels” use this test.

Several pet food manufacturers use plant glutens to bind ingredients. Kirk likened the use of gluten in pet food to the addition of eggs in meatloaf. “You need a protein structure to bind the meat and bread crumbs together,” she explained. Gluten performs the same function in pet foods and is commonly found in wet foods to thicken gravies. Rice gluten is oftentimes used with low-carbohydrate foods or in specialty diets for pets that have known allergies to meat proteins. It is also used as a thickening and binding agent, but Kirk said that it is not a common ingredient. In comparison, corn gluten is a very common ingredient in pet foods, she added.