Again, I will be closely following this story and will post updates regularly throughout the day.
Update 1:54 p.m ET: an exclusive source of ABC News, who is said to be "close to the investigation" has identified aminopterin, a rat poison that is illegal in the U.S., in the tainted food. It is not know if this is the only toxin. Strangely enough, aminopterin is used in the United States as a cancer drug.
We're still awaiting the press conference announced for this afternoon.
Update 5:20 p.m. ET: While awaiting the announced press conference, Dr. Janet Tobiassen Crosby, About.com Guide to Veterinary Medicine, has investigated the chemical properties and symptoms of ingestion of aminopterin. It is still unknown exactly how long it takes for symptoms of poisoning to present after ingestion. If any readers with affected pets would care to share that information, it may be very helpful to worried pet lovers. I know that is a large request at a time of grief and worry, but we are all in this boat together.
Update 5:46 p.m. ET:The results of the press conference are coming through now, and it is confirmed that aminopterin was found in tested recalled pet foods, having been found in two of three samples provided by Menu Foods to the testing agencies' scientists. How, exactly, it got there is still a matter of speculation. An official from the National Pest Management Association, said that it wouldn't make sense to spray a crop with rat poison, but added that grain shippers routinely put bait stations around the perimeter of their storage facilities, according to MSNBC.
Bruce Akey, director of Cornell’s diagnostic center was quoted as saying that in dogs and cats, the amount of the chemical found in the tested samples was a substantial amount (40 ppm) can cause kidney failure, and that that was a substantial amount. Although one chemist speculated that the aminopterin would not appear in pet food "unless someone put it there," Paul Henderson, CEO of Menu Foods discounts tampering, because the recalled products came from two different plants, in Kansas and New Jersey. He went on to state that Menu Foods intends to test every ingredient in these recalled foods. For those of us who wait and worry, better sooner than later, Mr. Henderson.