This is from Pet Connection's transcript of an FDA Press Conference. I think most of us here already had this info, but it's spelled our VERY CLEARLY here.http://www.petconnection.com/blog/
"So why did melamine suddenly start killing pets? Scientists now say it was combined with another chemical.
ALAN WILDEMAN, UNIVERSITY OF GUELPH: Well, I think we’ve identified what we feel is an important and likely underlying causative agent of why the animals are getting sick.
JOHNS: Scientists from Canada and the U.S. believe they may have unlocked a mystery. They’ve learned that melamine, combined with another contaminant found in the pet food, cyanuric acid, forms crystals in the kidneys.
WILDEMAN: What we’ve done is experiments that show, if you take cat urine and you add melamine to it, and cyanuric acid, the crystals will form in the cat urine in a test tube as you’re watching them. So it happens within a matter of hours.
JOHNS: It’s the crystals that are suspected of killing the pets. The ASPCA has seen a case that suggests that’s exactly what happened.
DR. LOUISE MURRAY, ASPCA BERGH MEMORIAL ANIMAL HOSPITAL: We actually had a case recently where the cat’s kidneys were completely obstructed. And when we went to surgery, to try to relieve the obstruction, there was no normal stone. Instead, the aortas were completely full of these melamine-type crystal.
JOHNS: And now the pet food investigation has turned into scrutiny of the human food supply."