The following is the AAFCO definition of chicken by-product meal in cat foot, either dry or canned:
"Definition: Chicken by-product meal consists of the ground, rendered, clean parts of the carcass of slaughtered chicken, such as necks, feet, undeveloped eggs and intestines, exclusive of feathers, except in such amounts as might occur unavoidable in good processing practice."
Fortunately, today, even most of the less expensive "grocery store" cat foods no longer list chicken by-products as an ingredient.
For example, from the first 6 ingredients listed for Friskies Savory Shreds Wet Cat Food (With Chicken and Gravy) Canned Cat Food:
"Water Sufficient for Processing, Chicken, Liver, Wheat Gluten, Turkey, Meat By-Products..."
Note that I have highlighted "Meat By-Products." While Friskies uses real chicken, liver, and turkey in this formula, "meat by-products" is even a nutritionally worse ingredient than chicken by-products would be. Chicken by-product meal is considered an inferior source of protein for cats. Although cats may eat a certain amount of by-products "in the wild," the most nutritious commercial cat foods will show a named meat, such as "chicken," as this particular brand of cat food does.
Unfortunately, the use of meat by-products negates the value of the chicken and turkey content. The AAFCO definition of meat by-products: "Meat By-Products are parts of slaughtered animals, not including meat (please note: no muscle meat included).
Included are lungs, spleen, kidneys, brain, liver, blood, bone, partially defatted low-temperature fatty tissue, and stomach and intestines freed of their contents."
Okay, don't cats in the wild hunt down game and eat their cats in its entirety? One of our Cats Forum leaders, HOSTDes, years ago, told the story of her feral rescue cat, Mr. 20 who, no matter how much nutritious cat food she provided him, insisted on jumping the fence to the property next door along with his cohorts, others Des had rescued.
The trespassing cats would catch and kill her neighbor's chickens, and eat every tiny morsel, except for the feathers. Des and her husband had a good relationship with their neighbor, and she wanted to keep it that way. She ended up negotiating with the neighbor to buy chickens from him each month to compensate him for the chickens Mr. 20 and his pals killed and ate.
So it isn't necessarily harmful for cats to eat the same thing they would eat in the wild. However, according to Susan Thixton, author of Buyer Beware, and founder of TruthAboutPetFood.com, the AAFCO is a bit 'dicey' in its adherance to Federal Law.
She has written a letter to the AAFCO President, Tim Darden, and Richard Ten Eyck, AAFCO Ingredient Definitions Committee Chair, asking for "swift action to correct these pet food safety issues."
Whether the AAFCO officials comply with her request remains to be seen.