About half of the 32 FDA investigators in the state have worked on responding to more than 500 complaints of sick or deceased dogs and cats since the recalls began on March 16. They must collect medical records from veterinarians and gather samples of contaminated pet food.

The office is also involved in recall effectiveness. "It's very taxing on our resources," said Scott MacIntire, director of the FDA's Chicago office, which oversees state operations.

MacIntire said his office is investigating a shipment of rice protein concentrate imported to Illinois and potentially used in a human product.

Nationwide, the FDA has only enough inspectors to check between 1 percent and 2 percent of the 8.9 million imported food shipments in 2006.

"We don't have the resources or the capabilities to test every single shipment of every single food item that crosses into our country or into our state borders," said Frank Busta, director of the National Center for Food Protection and Defense.

Stupak is one among a small number in Congress who for several years have pressed for stiffer food safety regulations. He said legislation likely to pass this year could include a provision giving the FDA authority to order food processors to recall questionable items.

Currently, the FDA can only issue mandatory recall orders for baby formula, while other government safety agencies have the ability to demand the recall of goods such as unsafe toys and tires.

"It took Menu Foods almost a whole month to do a full recall of the dog food," Stupak said. "If they're dragging their feet on the recall of dog food, in the meantime this tainted wheat gluten is going to hogs."

Other fixes could include expanded funding for food safety inspections and labs, the right to conduct spot inspections, subpoena power for the FDA and country-of-origin labeling on food products. Congress has already passed the labeling law, but the Bush administration has declined to implement it, citing cost concerns.

FDA officials acknowledged they are closing seven labs, but said they are older facilities that needed renovation, and that it is expanding other labs to compensate.s

The end of this pet food crisis appears more elusive than ever, shedding light on issues beyond the largely self-regulated pet food industry to America's growing dependence on cheap imported ingredients from China and other countries, where safety precautions may be more lenient.

But just as troubling, federal officials and congressional critics of the FDA say, is the ease with which the bad gluten was passed along once in the U.S. Food and water safety were an issue of great concern following the Sept. 11 attacks, they say, but those concerns seem to have eroded.

America's increasing reliance on low-cost food creates a complicated food distribution system, Busta said — and that leaves "many potential vulnerabilities."