The Pet Food Bible Blog

When selecting a high-quality commercial pet food, by-products can often be a source of confusion for both dog and cat owners. I’ve heard from many sources that, “The better brands of pet food do not use by-products.”

This may or may not be true. The fact is–-the concept is used mainly by pet food manufacturers to market their “no by-product” foods. I’ll admit that some by-products don’t belong in pet food. However, many by-products are a superior source of nutrition for our pets.

Keep in mind that just because something is “unfit for human consumption” it isn’t always unhealthy. Last I checked there wasn’t a huge demand in the human food industry for chicken hearts, pork livers, sheep lungs, or beef spleen. But these are all ingredients that offer our pets excellent nutrition.

Many by-products like liver offer superior nutrition over muscle meats when used in commercial pet foods. In fact, advocates of raw food diets don’t think twice about feeding certain “by-products” to their pets.

The main argument against by-products is that the quality will vary from manufacturer to manufacturer and from one batch of pet food to the next. The main problem is that it’s very hard to find consistency with by-products and many manufacturers are not specific about the types of by-products they use on the ingredient label. However, labeling all by-products as “bad” is simply teaching pet parents the wrong lessons.

In addition, there’s also the possibility that many by-products end up being re-routed from the human meat market to the pet food market because they may be showing signs of disease such as cancer or infection. I don’t have any proof or evidence that this is indeed the case, but I can’t imagine what exactly would be left over for pets once we’ve met our own quota for hot dogs, bologna, buffalo wings, McNuggets, and frozen dinners.

The AAFCO definition of “meat by-products” is as follows: The non-rendered, clean parts, other than meat, derived from slaughtered mammals. It includes, but is not limited to, lungs, spleen, kidneys, brain, livers, blood, bone, partially defatted low temperature fatty tissue, and stomach and intestines freed of their contents. It does not include hair, horns, teeth, and hoofs.

This can include ingredients that are both potentially healthy and unhealthy for pets. In essence, the amount of non-digestable material that a by-product contains will depend heavily on the ingredient supplier and the type of refinement process that the manufacturer uses.

So, does avoiding by-products in commercial pet food decrease your pet’s odds of acquiring horrible diseases like cancer, dog skin allergies, kidney disease and more? No one can say with 100% certainty. The choice to feed your pet by-products is more or less a personal decision. But keep in mind that the presence of by-products in a commercial pet food does not always indicate a poor-quality product. In fact, a food that has no by-products may have a large amount of second or third grade processed cereals which can be even less nutritious for our pets–-especially cats.