This is my tin-foil-hat theory. Take it for what it's worth.
http://en.wikipedia.org/wiki/MelamineMelamine is produced from urea, mainly by either of two methods: catalyzed gas-phase production or high pressure liquid-phase production.
Urea is a byproduct of metabolism but too much can cause liver and kidney failure.
http://en.wikipedia.org/wiki/UreaThe urea is formed in the livers of mammals in a cyclic pathway, from the break down of ammonia, (a metabolic waste), which was initially named the Krebs-Henseleit cycle after its discoverers, and later became known simply as the urea cycle.
http://www.ext.colostate.edu/Pubs/livestk/01608.htmlUrea can be fed to ruminants as an economical replacement for a part of the protein in a ration.
The amount of urea a ruminant animal can use depends on the digestible energy or total digestible nutrients (TDN) content of the ration.
No more than 0.1 to 0.25 pound urea per head per day should be fed to feedlot cattle consuming a high concentrate ration.
Toxicity should not be a problem if urea is fed according to recommendations.
Vinegar is a helpful emergency treatment for urea poisoning if the animal is treated before tetany develops.
Perhaps some unscrupulous feed lot operator jacked up the Urea content in the feed hoping to put on a few extra pounds in the cattle, taking the risk that a few might die from urea poisoning or the cattle were dehydrated due to cold weather and were unable to get enough water and died.
So, what happens to the cattle that die? They get sent to rendering plants where the carcasses are converted to 'Animal Protein', which is sold to pet food manufacturers.
http://www.nexusmagazine.com/articles/petfood1.htmlFOOD NOT FIT FOR A PET
by Dr Wendell O. Belfield, D.V.M.
The most frequently asked question in my practice is, "Which commercial pet food do you recommend?" My standard answer is "None." I am certain that pet-owners notice changes in their animals after using different batches of the same brand of pet food. Their pets may have diarrhoea, increased flatulence, a dull hair coat, intermittent vomiting or prolonged scratching. These are common symptoms associated with commercial pet foods.
In 1981, as Martin Zucker and I wrote How to Have a Healthier Dog, we discovered the full extent of negative effects that commercial pet food has on animals. In February 1990, San Francisco Chronicle staff writer John Eckhouse went even further with an exposé entitled "How Dogs and Cats Get Recycled into Pet Food".
Eckhouse wrote: "Each year, millions of dead American dogs and cats are processed along with billions of pounds of other animal materials by companies known as renderers. The finished product...tallow and meat meal...serve as raw materials for thousands of items that include cosmetics and pet food."
Here's the scary part:
The animals that don't die get sent to slaughter and the livers and kidneys, also known as meat by-products go into processed meats.
http://www.time.com/time/magazine/article/0,9171,906490-1,00.htmlTo Nader, the ABM and the smart bomb are scarcely more lethal than a chain of processed sausages. Hot dogs, insists the consumer advocate, are "among America's deadliest missiles."
http://www.nader.org/template.php?/archives/653-Frank-Talk-About-Frankfurters.htmlWhat's in a frankfurter? This question is being answered with disturbing detail for consumers who want to know what they are buying. Fraud, low nutritional value and health hazards abound, with varying degrees, in most of the 15 billion frankfurters sold annually.