Aside from globalization, factory food, homeland security, and personal tragedies, the aminopterin poisoning of 2007 has shed some light on the pet food industry. Emphases mine. I admit, I was surprised to learn that pet food is less rigorously regulated than cow feed -- because we don't eat pets ...
Pet Food - Pets - Menu Foods - Poisonings - Dogs - Cats - New York Times
.... Q. What’s in pet food then? Is it regulated?
A. Pet food is regulated by the F.D.A. through the same state agencies that regulate food for farm animals. But product excluded from animal feed can go into pet food — meat and bone meal, nervous system tissue — parts of animals not allowed for anything else. There were cases of mad-cow disease in cats in England. The opportunity for cheap byproducts is much greater in pet foods. The assumption is that better brands don’t do that, but it’s not verified.
Q. If a few companies are making many of the brands, are pet foods all the same then?
A. Nutritionally, they have to meet the same industry standards, though they’re priced very differently. You read the labels and they all look alike — corn is the first ingredient in a lot of dry food.
Q. Why are some brands more expensive?
A. The quality of the ingredients. Are you using human-grade food or food that humans wouldn’t care to eat? It doesn’t matter to animals but it matters to the people who own them.
Q. What about health claims?
A. When you see food claims on breakfast cereal — for instance, that it lowers cholesterol — there has to be some scientific substantiation behind them. Pet foods have claims on them, that they support a healthy immune system, reduce risk of whatever, but they don’t have to be supported by large amounts of science. They’re worded in such a way that doesn’t violate the F.D.A.’s labeling rules. I think the F.D.A. will have to take a much closer look at pet foods — this is the second recall in a short time.
Q. What do cats and dogs enjoy eating?
A. Cats don’t have a taste for sugar; they don’t taste sweet things. They have a particular taste for what is referred to in the industry as “animal extract” — God knows what’s in it. Dogs can taste sweet, but, dogs will eat anything. Cats are very fussy, as any cat owner will tell you. The one thing that’s never been studied is to find out how long it would take for a cat to eat something it doesn’t like — owners never wait it out. People are very attached to their pets, and it’s painful to watch a cat not eat.
Q. Should owners prepare their own food for pets or feed them table scraps?
A. There’s evidence that dogs can be fed table scraps and do quite well, provided they’re healthy table scraps — meat, dairy, vegetables, fruit. The problem is a lot of humans don’t eat that way.
A mixture of expensive "organic" pet food and healthy table scraps sounds good and perhaps relatively cost-effective. It's impressive how little we know about whether our "premium" pet food is really very premium at all.