Eating plasticized piss is not a good idea

Pay more to unknowingly feed congealed urine to your loved ones.
So large corporations can make fractionally more money.
It is one of these framing issues, see.

More problems with pet food.
Recall expanded and clear that contaminated "protein" made it into the human food chain.

To cut a long story short, since this is all over the media; chinese producers figured they could inflate the nitrogen assay of vegetable protein by adding cheap nitrogenous compounds.

A favourite seems to be Melamine - a polymer of cyanamide, very high nitrogen content by mass. For extra layman yuck factor, it is synthesised from urea.
It is useless, or worse, as a metabolite, but as scrap material left over from plastic making it has the virtue of being very cheap. Literal scraps are barreled and auctioned, they are then ground up and deliberately poored into batches of low quality vegetable protein to make it test to have higher nitrogen content. Several percent by mass is melamine, apparently, in some cases.

It kills cats and dogs, by destroying their kidneys, not clear if it does so directly or if breakdown products, contaminants or metabolites are involved.
It is at best not good for humans, at worst it is also poisoning people, if not as acutely as cats.
It is also fraudulent and criminal to be selling it to us in the guise of protein.

Looks like finally something will be done, maybe even something effective, but we have not heard the end of this yet. Also wonderfully highlights another major vulnerability in society.

More info below.

itchmo - pet blog, informative

petconnection - more professional grade pet info

FDA - slow but authoritative in so far as they got

also on effect measure

Oh, what is it in, other than pet food?
Animal feed - animals that were raised for human consumption.
Most processed foods, including anything with sauces, gravies, binders or thickened fluids.
Some baby food. A lot of grain based food, where it is listed as gluten or added protein.

How much is there out there? Not known. FDA was very slow to investigate and does not seem publicly to be really throwing their weight around. Could be occasional small batches, could be most imported grain gluten or derived protein. Apparently a lot of previously US produced gluten has been pushed off market by imports, because they are cheaper enough (despite the decline in the dollar) to be worth shipping.

PS: Ok, urea is not actually extracted from urine commercially, much.
Direct synthesis from ammonia and CO₂
It is still something we should be excreting, not ingesting...

PPS: a figure that stuck in mind, but that I can't track down, is that the producers made an extra $4 per ton by using melamine instead of actual protein additives.

PPPS: as with pets, any health problems are likely to show up in elderly, very young or already ill.
Does the CDC track, for example, kidney failure incidence in the elderly? 'Cause even a small percentage of premature deaths due to kidney function failure would be large numbers globally, but almost unnoticable locally, and probably not reportable the way infectious diseases or clear poisonings would be.
Of course, IF it has any health effects on humans, they need not be fatal. Maybe it'd just increase the incidence of kidney stones, or urinary tract infections... painful, but rarely fatal.

PPPS: CDC does track nephritis as cause of death - was at just under 2% in 1999
doesn't look like data is continuously updated, more like a year or two to get aggregate data out
It is confounded by the fact that death rates due to kidney failure are increasing anyway, partly i suspect from diabetes related complications, and partly from general increase in age and ability to cure or defer other causes of death.