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Pet Food Ingredients: The Questionable

Unfortunately, artificially coloring pet food only appeals to owner preference and does not promote pet health.

This article originally appeared on my ongoing series of articles for Flexcin International, Inc as Pet Food Labels: Questionable Pet Food Ingredients

As part of our “Reading Pet Food Labels” series, we covered the basics along with the ‘Good’ and ‘Bad’ ingredients. Now it’s time to cover the ‘Questionable’ ingredients you may find in your pet’s food or treats.

The questionable nature of these ingredients stems from their potential to be toxic. They may not cause clinical signs of illness from occasional consumption, but their cumulative effects could be deadly. If your pet regularly eats food or treats made with these (and other) ‘Questionable’ components, his or her health may be at risk.

Questionable ingredients:

‘Meals’ and ‘By-Products’

  • ‘Chicken meal’, ‘meat by-product’, ‘soybean mill run’, ‘wheat gluten’, ‘hydrogenated starch hydrolysate’ and other hard to pronounce ingredients listed on your pet’s food or treats indicate processed ingredients that could potentially be harming your pet.
  • Meat ‘meals’ and ‘by-products’ come from the rendering process (see below) and can contain “dead animals from farms, ranches, feedlots, marketing barns, animal shelters, and other facilities, as well as fats, grease, and other food waste from restaurants and stores.
  • A popular trend in the pet food industry is to make food that is grain free. I believe there is some merit to this. Grains are not necessarily bad for your pet, but most pet foods contain fractionated, ‘feed grade’ grains instead of the whole grains suitable for human consumption.
  • Fractionated grains have been broken down into individual components used to satisfy industry requirements for protein, carbohydrates, fat, and other nutrients; this way, production costs can be lowered by using cheaper, not whole food based ingredients.

When feeding your pet, focus on whole foods instead of processed meals and treats.

Rendered Fat and Animal Digest

  • Both rendered fat and animal digest are by-products of the rendering process. Rendering attempts to make something useful from a variety of animal parts, including those belonging to ‘dead, disabled, diseased, and dying’ (the 4Ds) animals.
  • Los Angeles County Government document reports “the majority of rendered materials are remains of cattle, hogs, poultry, and sheep – the parts that cannot be sold for meat, leather, or other products. Other animal remains, such as butcher scraps, restaurant grease, fish, zoo animals, marine life, and animals from shelters are rendered as well.”
  • After dry food is cooked at a sufficiently high temperature to reduce moisture and kill bacteria (which also deactivates beneficial enzymes and denatures protein), it is sprayed with rendered fat.
  • Unfortunately, rendered fat can be a source of both microorganisms and toxins. If moisture is introduced to the food, bacteria and mold are able to thrive.

Why use a potential toxin to coerce your pet to eat? Avoid foods, treats, and supplements having rendered fat and animal digest.


  • This common ingredient in canned pet foods helps maintain consistency and moisture. According to the International Agency for Research on Cancer, there is “sufficient evidence for the carcinogenicity of degraded carrageenan in animals to regard it as posing a carcinogenic risk to humans.”
  • So, the ‘glistening meatloaf’ appearance of your pet’s food is due to the addition of carageenan which could be contributing to the development of cancer.

Cut the carageenan out of your pet’s diet.

Food Dyes

  • Blue 2, Red 40, and Yellow 5 and 6 have been documented to contribute to hypersensitivity (allergic-type) reactions, behavioral problems, and cancer in humans. More recently, caramel color has come under fire as it contains 4-methylimidazole (4-MIE), a known animal carcinogen.

Instead of serving a meal that is artificially colored, provide foods having naturally bright and deep colors that contain beneficial anti-oxidants, vitamins, and minerals such as fruits and vegetables.

Meat and Bone Meal (MBM)

  • If your pet’s food contains ‘meat and bone meal’, then you could be serving a daily dose of pentobarbital. Pentobarbital is a barbiturate anesthetic used to euthanize animals.
  • According to the Truth about Pet Food, you have to keep a keen eye on the ingredients listed because ‘Meat and Bone Meal’ could also be listed as Animal Protein Products (collective term).

For the sake of your pet’s best health, avoid the ‘Bad’ and ‘Questionable’ ingredients.

Related Articles

Pet Food Ingredients: The Bad

Pet Food Ingredients: The Good

Why You Should Closely Scrutinize Your Pet’s Food and Treat Labels

Human Foods That Make Great Pet Treats

Photo Credit: Flexcin International, Inc.

Thank you for reading my article.  Your questions and comments are completely welcome (I’ll respond).

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Copyright of this article (2012) is owned by Dr Patrick Mahaney, Veterinarian and Certified Veterinary Acupuncturist. Republishing any portion of this article must first be authorized by Dr Patrick Mahaney. Requests for republishing must be approved by Dr Patrick Mahaney and received in written format.

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