What actually killed our pets?

Another great post from Gina at Petconnection

The Canadian press had this reported pretty widely a couple of days ago — and it’s blogged in here somewhere. But now the AVMA is saying what may have killed the pets who ate the tainted pet food:

Tests conducted on contaminated pet food and necropsies from affected animals have resulted in a new theory to explain how animals are being adversely affected by contaminated pet foods. A chemical reaction between melamine and cyanuric acid is suspected of forming crystals and blocking kidney function.

The investigation into contaminated pet food has focused on melamine contamination of ingredients imported from China, such as wheat gluten, rice protein concentrate and corn gluten (imported into South Africa). It is now believed that cyanuric acid, as well as melamine, has been found in urine samples from animals that died.

Analysis of the crystals in the kidneys of affected animals have revealed that they are approximately 70 percent cyanuric acid and 30 percent melamine, and are extremely insoluble. Furthermore, tests mixing melamine and cyanuric acid in samples of cat urine resulted in almost immediate formation of crystals that were identical to crystals found in the kidneys of affected animals. Two other melamine- related substances—ammelide and ammeline—may also play roles and are under investigation.

Here’s the rest. And here’s the Toronto Star, from three days ago:

Guelph scientists may be closer to figuring out why North American pets are dying from contaminated food.

Two of the chemicals U.S. authorities say they’ve found in food additives from China – melamine and cyanuric acid – can react to form crystals that could block kidney function, according to the University of Guelph’s Agriculture and Food Laboratory.

The U.S. Food and Drug Administration found melamine, which is used to make plastic, in wheat gluten and rice protein concentrate in some pet foods. They’ve also found cyanuric acid, a chemical used to treat water in swimming pools, in wheat gluten.

So far, 16 pets have died, but experts say that number is low. Dozens of contaminated pet food products have been recalled.

“This is a piece of the puzzle, a significant finding,” said John Melichercik, director of analytical services for Guelph’s laboratory services. “We have found these crystals in cats that have suffered renal failure.”

American health authorities have implicated the two compounds, but because neither seemed sufficiently toxic on its own, it was unclear how they were involved. But both compounds are something “you wouldn’t expect to see in pet food,” Melichercik said.

Here’s the rest.