The Shocking Truth About What's in Your Cat Food, Part 2

The shocking truth about cat food

We talked in Part 1 of this series about the ins and outs of pet food labels and ingredients, and the role the FDA plays in regulation. Now it's time for us to look at some of the actual ingredients you might find in your cat's food, and what they really mean. Don't panic if you see any of these ingredients listed on the cat food in your pantry right now. The best thing to do is check the labels on alternative brands the next time you’re shopping, then talk with your veterinarian about your cat's diet and health before you make any changes. 

Ingredients to Watch Out For:

Meat Byproducts/Meal Meal/Meat & Bone Meal

These ingredients come from rendering plants and can consist of all kinds of processed animal parts from 4-D poultry and livestock (dead, downer, diseased and dying), including diseased organs and glands, bone, decayed muscle and rancid fat. Believe it or not, even euthanized pound and shelter pets can end up in these products. This stuff is mixed together, cooked at high temperatures, dried, and ground into meal. It often contains antibiotics from previously treated dead and downer livestock as well as small bone splinters and other contaminants. The meal may be treated with artificial preservatives to inhibit rancidity and the growth of pathogens. It does not, however, contain hooves and hides, which are used for other purposes. 

Animal Digest 

Basically the same as meat byproducts except it can include spoiled restaurant and store meats deemed unfit for human consumption. 

Animal Fat

Since this ingredient is unnamed, meaning it is not species-specific, it can be sourced from anywhere from any kind of rendered 4-D animals, even road kill and dead zoo animals. The potential for pharmaceutical or other contamination exists, and chemical preservatives are commonly added to this fat to inhibit rancidity.

Poultry Byproducts/Poultry Meal

This ingredient is also similar to rendered meat byproducts, except it consists of all the non-meat poultry parts, including guts, feet, beaks, waddles and feathers. This may also contain traces of antibiotics from birds that died on the farm.

Corn/Corn Meal

Grains, especially corn, offer no significant nutritional value to cats. Cats are prey-hunting obligate carnivores ("obligate" means they MUST eat meat to survive) with digestive systems developed for all-meat diets. They lack the necessary enzymes to properly digest grain starch, so the nutrition that’s available to other species from corn cannot be used by cats. Corn is high in sugar and low in protein, so cat foods containing corn provide an unhealthy diet for cats. This can lead to malnourishment, overeating, feline diabetes, obesity and other health problems.

Other Grains

This would include barley, oats, rice and wheat, which are nothing more than hard-to-digest, unnecessary carbohydrate fillers in cat food. Although these small grains are slightly more digestible than corn, cats simply did not evolve as grain eaters, so these should not be in your cat's food. Cats may overeat food containing grain because it leaves them feeling unsatiated. They need meat protein to control their appetite and maintain a healthy body weight.

Grain Byproducts

You may see ingredients on your cat food called things like grain fractions, rice hulls, grain hulls, milled barley, wheat mill run and wheat middlings. These grain milling byproducts are actually worse for cats than the grains discussed above. They are a trash ingredient often contaminated with dead insects, bird droppings, vermin feces and other dirt. These are non-digestible, cheap fillers that have no place in a cat’s diet.

Soy/Soy Byproducts

Soy products are known to have serious health consequences for both cats and dogs and should not be present in their foods and treats. Soy in your cat’s diet can adversely affect amino acid absorption, leading to malnourishment. It can also be allergenic, cause gastric upset, and may cause clumping of red blood cells. However, every major pet food brand uses soy in one form or another, often masking it on the package label under names like “vegetable protein” or “textured vegetable protein.” Why do they add soy? Because, compared to meats, soy is a cheap protein substitute that increases profits. Soy also pushes up the percent crude protein in order to make the guaranteed analysis seem complete and balanced.

Wheat Gluten/Gluten

If the cat food label lists this or any other gluten source, put it back on the store shelf and look for another product. Regardless of whether the gluten came from wheat, corn, rice, or any other grain, it is bad for your cat. Gluten is very allergenic for many cats, as well as dogs and some people. It can cause severe intestinal distress in cats and dogs, including potentially lethal bloat.


Both of these are useless carbohydrates for cats that are sometimes added as a sweetener to enhance flavor or to boost calories in kibbles for growing kittens. Either of these can cause food addiction in cats and dogs, which leads to overeating, obesity and possibly diabetes.

Food Dyes

These coloring agents have only one purpose in cat or other pet foods. They are added to make the food appealing to humans and thus sell more product. Dyes are in the food to mislead pet owners into believing there is some sort of fresh, natural wholesomeness in the food – your cat couldn’t care less.


The common ones to watch out for are: 

  • BHA and BHT – Also known as butylated hydroxyanisole and butylated hydroxytolulene, both of these chemical preservatives are known to be carcinogenic. These are typically added to pet foods that contain added meat meals, fats and oils to prevent rancidity and inhibit microbial growth, thus extending package shelf life. BHA and BHT can build up in your cat’s tissues over time, which may lead to certain types of cancer and other conditions. 
  • Propylene Glycol – This is a very toxic industrial solvent and a component of antifreeze. It is a very sweet preservative that entices cats to be less finicky about their food so they’ll eat more. This gimmick ingredient tricks owners into thinking they've finally found a food their cats love. The downside is that it destroys red blood cells, which can obviously be lethal. 
  • Ethoxyquin – a chemical preservative and known carcinogen that is illegal to add to human foods in the U.S. That alone should tell you to run from any cat food that lists it. Ethoxyquin can show up in tested pet food, even though it’s not on the list, if the food contains contaminated fish or meat meals. The most troublesome are fish and meat byproducts that are imported from China – another reason to avoid those ingredients. Ethoxyquin is still approved as GRAS by the FDA for pet foods.

So What Should I Do?

Commercial pet food companies are not out to get our cats and other pets, but for them it’s really all about their market share and the bottom line. For pet owners like you and me, the bottom line is all about the health, wellness and quality of life we can provide for the cats we love. To provide healthy, nutritious, safe foods for our feline companions, we have to be proactive consumers, willing to learn about the cat products we buy. Make sure all the pet owners in your life know the truth about pet food ingredients, and how to make the best possible choices for their furry friends. If you have any recommendations for healthy cat foods you like, please leave them in the comments.

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