I don't know about E-312, E-320, and E-321, but you are very correct about BHA, BHT, and ethoxyquin. They've been known to cause many problems, including cancer and epilepsy. Ethoxyquin is illegal in human foods in North America, and BHA/BHT became illegal in human foods in California when they were tested positive as carcinogenic (cancer-causing). Other places have only put a limit on how much BHA/BHT can be used in a food. You most often find them in cereal or cereal packaging. It's disgusting.

It's not only the preservatives you need to look out for. There are other disgusting ingredients. Roadkill, euthanised pets, and rotten or 4-D foods not fit for human consumption. Pet food is one big business with a load of profit. I really commend those pet foods out there that are spending money on the quality of their food and not the advertising. That's what it's all about -- quality food and health for our pets.

Pet Food -- Our Pets are Dying for it
The truth about commercial Pet Food