Pet Detectives Work Hard, but Deaths Are Tough to Solve

Apr 06, 05:00 AM

Current Headlines: By Elizabeth Weise and Julie Schmit

Weeks have passed since pets started dying after eating tainted pet food, and animal lovers want to know why it's taking so long to figure out why.

The answer they're getting -- that it takes time -- is not what they want to hear. But experts say that identifying an obscure contaminant in food is the scientific equivalent of looking for a needle in a haystack.

Although one culprit is now the focus, scientists don't know how the fairly non-toxic chemical led to kidney failure in reportedly hundreds or thousands of pets in what is one of, if not the, largest pet-food recalls in history. In the world of toxicology, there's no CSI: Pet Food team to sweep in and solve the puzzle.

"It's not that easy," says Rich Catalani, executive story editor of the original CSI television series. "One of the things we short-cut is the long, boring, technical analysis. We have a guy in front of a microscope for a minute. The reality is that he may sit there for eight hours or more."

Newspapers nationwide quote pet owners crying out for justice. For her part, Bobbie Stadler, a plant nursery owner in Salisbury, Md., who has three dogs and one cat, says, "I don't feel that anybody's on top of it, and I'm really worried it's going to have further repercussions. I don't feel reassured by anybody."

The Food and Drug Administration said Thursday that it has received 12,000 complaints from consumers regarding the pet foods -- more than twice the number of complaints the agency gets all year for all products -- and is testing hundreds of samples.

The FDA doesn't know how many animals have been affected because it hasn't had time to investigate claims. It has confirmed about 15, mostly cats, but unconfirmed reports indicate the number is far higher; even the FDA expects it to climb. The investigation continues. After an initial finding of rat poison in samples of wet cat food by a New York lab, the FDA and industry have turned their focus to melamine, a chemical used in Asia as fertilizer.

The melamine find was initially made not by the FDA, nor by any university labs involved in the search, but by a pet-food maker: Procter & Gamble, which makes Iams and Eukanuba, the FDA says.

Canada-based Menu Foods -- which produces pet food under nearly 100 labels, including some Iams and Eukanuba types -- in mid-March recalled more than 60 million cans and pouches of wet dog and cat food. Last week, three other pet-food makers announced smaller recalls. On Thursday, Menu expanded its recall, and another firm recalled dog biscuits.

The melamine somehow got into wheat gluten exported by a Chinese firm, Xuzhou Anying Biologic Technology Development, the FDA says. That firm exported to ChemNutra, a Las Vegas-based importer, which reports selling the gluten to three pet-food manufacturers and one distributor who supplies the pet-food industry. Wheat gluten is used in wet pet food as a binding agent and protein source.

All indications are that the tainted gluten never entered the human food supply, the FDA says. But other mysteries remain, chiefly the fact that limited scientific literature, most involving rats and dogs, doesn't indicate that melamine is toxic enough to explain the large number of reportedly affected animals. "We still have a lot of work to do on why melamine," said Stephen Sundlof, the FDA's head of veterinary medicine Thursday, adding that nothing is conclusive so far.

"It's certainly not a perfect candidate," says Steven Hansen, director of the ASPCA's Animal Poison Control Center in Urbana, Ill. "If you took the amount of melamine that we think is in one can, it would take about 50 cans (of pet food) to get to a lethal dose for a cat, based on the studies we have in rats.

"It's quite a mystery," he says. "The story that we all expected to be bad and get over very quickly is still not answered."

An army of researchers

Attempting to identify the mystery molecule that has reportedly sickened cats and dogs across North America is involving hundreds of researchers, tens of thousands of dollars and a lot of shoe leather. The FDA says that about 400 employees are collecting pet-food samples, monitoring recall effectiveness, and preparing consumer complaint reports.

At its Emergency Operations Center in Rockville, Md., the FDA has a conference room devoted to the task. The walls are papered with maps and summaries of data; a large table is dotted with conference-calling phones. As often as once a day, the agency links representatives from affected districts, the Center for Veterinary Medicine, the Center for Food Safety and laboratories in a call that can last up to two hours and involve up to 100 people. The group gets an update on what's known, discusses the facts, identifies new leads and decides the investigation's direction.

The FDA won't reveal everything, but interviews with more than a dozen experts in the fields of forensics, toxicology and epidemiology offer a glimpse of how many steps there are to solving the puzzle.

The first, and perhaps most crucial, was the decision by Menu Foods to tell the FDA -- without knowing what the problem was -- that something was up. The company's openness probably saved thousands of cats from a horrible end, says the ASPCA's Hansen.

Not everyone agrees. Lawsuits are mounting, including a Chicago-based class-action filing that accuses Menu of fraud and negligence.

The company had contracted with an outside agent to conduct a feeding trial for taste, a continuous industry practice; on March 2, it received reports that three animals were getting sick. The week of March 12, the taste-test company told Menu that nine animals had died, says Menu spokesman Sam Bornstein. After confirming that it was Menu's food that had been consumed, the company informed the FDA on March 15. "Honestly, without those results, it would have been hard to relate it (the deaths) to foods, especially because in this case, the foods are under so many labels," Hansen said.

Menu's call to the FDA set off a cascade. The agency activated its Emergency Operations Center, and as word of the recall spread, vets began reporting deaths of cats and dogs they had previously chalked up to other causes. They also sent in tissue samples.

"You have to start off thinking like Sherlock Holmes," says Douglas Stickle, director of the Chemical Terrorism Preparedness Laboratory at the Nebraska Public Health Laboratory in Omaha.

"You put (the sample) under a microscope and just look at it and say, 'Does it look like it's supposed to look?'" he said. In the case of the poisoned pet food, it didn't. There were microscopic yellowish crystals in the urine and microtubules of the kidney.

But knowing the crystals were causing the kidney failure didn't answer the $100,000 question: What was causing it?

Samuel Cohen, chair of the pathology and microbiology department at the University of Nebraska Medical Center in Omaha, is an expert on urinary tract problems. Veterinary pathologists began e-mailing him images of what they were finding in mid-March asking if he could identify them. He couldn't.

Many of the country's top toxicologists spent the week of March 25 in Charlotte at the Society of Toxicology annual meeting. The mystery of the pet food was a major topic of conversation, Cohen said. But melamine "wasn't the first thing that jumped to the front of anybody's mind," he said.

During all this, FDA investigators were visiting Menu Foods and its suppliers and inspecting their plants. They quickly zeroed in on wheat gluten. Menu had changed a supplier, the only alteration in its manufacturing process.

But even suspecting the gluten left a universe of potential chemicals. General screening tests look for hundreds of chemicals at once. With the obvious out of the way, tests for more obscure chemicals, such as melamine, must be done one by one. Used to make plastics and as a fertilizer in Asia, it's nothing anyone would expect in U.S. pet food.

"There are millions of different molecules, many of which are normal parts of food. To try to pull out what molecule is there that shouldn't be is a significant task," said James Popp, president of the Society of Toxicology. "It can take weeks."

Chemists might start with an infrared spectrometer, which makes chemical bonds in a sample vibrate. "¨You can get a very good fingerprint of individual molecules based on the pattern of vibrations," said Stickle.

Next might come liquid chromatography, which separates compounds using chemical properties. Further information on chemical composition can be obtained by a machine called a mass spectrometer, which determines the mass of the molecules, which can help pin down what the molecule is.

The machines involved are the size of large copiers and cost between $150,000 and $500,000.

CSI sleuths have it easy; they deal only with humans, said Alex Ardans director of California's Animal Health and Food Safety Laboratory System. "In an animal laboratory, we deal with multiple species, all with different sensitivities. That's the challenge for veterinarians, to be conversant in a number of different species."

Cornell has key role

After the FDA got the melamine tip from Procter & Gamble, the agency passed that information on to other labs, including one at Cornell University.

Within two hours of getting the FDA call on March 26 -- and now knowing what to look for -- Cornell found the melamine, too, after re-analyzing data that had already been run, says Donald Smith, dean of the College of Veterinary Medicine at Cornell University. Cornell promptly called the FDA.

Having found melamine in both the pet food and the wheat gluten, Cornell solidified its research the next day with melamine finds in cat urine samples and kidney tissue, Smith says. The FDA announced the melamine discovery three days later.

Cornell has a history with pet-food recalls. In 2005, it took it just one day for it to identify aflatoxin, a mold toxin, in corn used by Diamond Pet Foods, which led to liver failure in dozens of pets.

But melamine, unlike aflatoxin, was not high on the list of suspects. For much of March, Cornell scientists -- tapped by Menu -- weeded out more obvious culprits: mold toxins, heavy metals such as lead, arsenic and mercury, and even antifreeze, says Cornell's Smith.

Because melamine is not viewed as highly toxic, Sundlof says the probe is now focused on whether it is the cause of pet deaths or a marker that indicates the presence of something else. Another question: Are cats and dogs more sensitive to melamine than rodents (the subjects in most of the research)?

While the lulls between discoveries and action might seem long, Robert Poppenga, a professor of clinical veterinary toxicology at the University of California at Davis, points out that in science, one discovery does not the truth make. "Part of the delay is you find something and then you run it again to make sure it's right. You check. You don't want to put out bad information," he said. "That's worse than no information." (c) Copyright 2005 USA TODAY, a division of Gannett Co. Inc.