Apparently, the Iowa State University Veterinary Diagnostic Lab has been the main instituition examing tissues from the animals that have dies due to the pet food recall. Here is some text from the website detailing some of their findings:
"Autopsy and microscopic examination of tissues from affected animals indicate acute renal toxicosis including the presence of birefringent crystals, as well as other crystal formations. The effects are consistent with exposure to ethylene glycol and derivatives, mycotoxins, ochratoxin and citrinin, some heavy metals or vitamin D toxicity. At the present time the exact cause of this problem is not yet known. Investigations are continuing."
The full report can be read here. Definately bad news for the animals, their owners and the pet food manufacturer. However, it is great that the ISU pathologists are on top of this national problem!