you're kidding me... wikipedia to end an argument over 15+ yrs of experience and studying... not realistic... also there is more to it... there is a cation exchange and if the exchange rate is not correct than it can cause many problems... i almost broke a world record with a kidney stone at 25 yrs old.
as for your reference link... the first paragraph stresses importance of quality... quality for dogs, herps, and humans are way different. second paragraph clearly states protein nutrition is still not completely understood. and when did nature start manufacturing the products we see in the market??? note: dogs can pass extra proteins at will with no harmful side effects in most cases... not every animal can!
here is the first 2 paragraphs:
"
The article referenced below does not show protein as a problem, but rather states the importance of it in a dog’s diet. The need for a high quality protein is explored in puppies and throughout all stages of a dog’s life. While the article admits that not everything is known about protein and dogs, excess protein is not a problem given in amounts greater than recommended, as long as the quality of the protein is good.
PEDIGREE
“Protein nutrition is obviously still not completely understood, however it is an essential part of every dog’s diet. You can’t give too much protein in your dog’s diet; however quality not quantity makes the difference.”"
and who exactly do you think gnc caters to... body builders, health nuts, naturalists who have been led astray by marketing and hippies who need urine cleaners! if it wasn't for body builders gnc would have never got off the ground!