The Canadian Food Inspection Agency is on the lookout for vegetable proteins imported from China as a pre-emptive measure to prevent possible contaminants from entering the human food chain, CBC News reports.
The precaution follows contaminated wheat gluten that sparked a massive recall of pet food.
The agency is concerned that similarly tainted products could make their way into products destined for people.
The CBC says that agency inspectors will seize Chinese shipments of products including wheat and corn glutens and soy and rice proteins.
An agency spokesman said the shipments will be held for testing before they are released.
Imported wheat gluten laced with melamine was blamed for killing at least 16 pets and sickening hundreds of others.
Vegetable proteins are found in many products, ranging from baby formula to pizza dough to wieners.
Canadian manufacturers do not have to declare what country the ingredients come from -- or routinely tell the government unless there's an investigation.
Yesterday, researchers in Ontario at the University of Guelph suggested that a chemical process that occurs between two compounds, one used to make plastics and another employed in pool chlorination, may explain how North American pets were affected by the recalled pet food products.
Cyanuric acid, which was found in urine samples from animals that died, and melamine, a compound identified in the gluten found in the recalled pet food, react with one another to form crystals that may block kidney function, researchers at the university said yesterday.
"You wouldn't normally expect to find those compounds in pet food, and hence nobody was really looking for it," said John Melichercik, director of analytical services for laboratory services.
"It's just another piece of the puzzle along the way in this particular pet-food issue."
Last month, Ontario-based Menu Foods recalled 60 million cans and pouches of its "cuts and gravy" style food, sold under 95 different brand names, for fear of contamination after it received reports of kidney failure and even death among dogs and cats.
Federal testing of some recalled pet foods, and the wheat gluten used in their production, turned up the chemical melamine, commonly used to make kitchenware and other plastics.
Further testing done at the University of Guelph and a number of U.S labs found that cyanuric acid, a metabolic byproduct of melamine, was also found in the urine and tissue samples of affected animals.
Last week, a chemist at the Agriculture and Food Laboratory in Guelph decided to test the reaction between the two compounds in a setting similar to that of an animal's kidney.
"Our research had taken a number of turns, and so we decided to take a look at the two substances implicated by the FDA," Mr. Melichercik said.
The experiment resulted in the formation of a precipitate in a crystal-like form. Analysis of the crystal determined that it had a chemical fingerprint matching that of crystals found in the urine and tissues of animals that died of renal failure.