Human-Grade Foods Are Better for Pets Than Animal-Grade Foods - Part 2

Written by:

Patrick Mahaney, VMD, CVA, CVJ
Published: March 04, 2016

As you know, if you are a regular reader, my dog Cardiff is thriving despite being under long-term chemotherapy for his second emergence of T-Cell Lymphoma.

I generally see that my patients who eat whole-food diets throughout their lives have fewer health problems. Additionally, my patients who consume whole-food diets that are undergoing chemotherapy, including Cardiff, often digestively tolerate treatments with cancer-killing chemicals better than those eating processed pet foods like kibble and most canned options. This means an improved appetite with less vomiting and diarrhea, which lends to the owner’s perspective that chemotherapy isn’t negatively impacting a pet’s quality of life.

Now that you’ve read Part 1 of this article (see Processed Food vs. Whole Food for Pet Cancer Patients — What’s Better?), we can continue on to Part 2 of my holistic veterinary perspective on this topic.

What’s the Differences Between Processed vs Whole Foods?

Commercially-available kibble and many canned pet diets undergo significant processing to achieve the final product and are thereby considered processed foods. Processed pet foods contain fractionated ingredients, like meat and grain "meals and by-products," which either don’t exist in nature or are radically changed from the form nature created.

Conversely, whole foods appear identical or very similar to their natural form. Whole foods contain vitamins, minerals, carbohydrates, proteins, and fats that are best assimilated when consumed in combination. By breaking nutrients apart (fractionating), foods’ synergistic qualities can be lost, and the co-factors essential for digestion may be lacking, which can lead to poor absorption of nutrients and digestive tract upset (inappetence, vomit, diarrhea, etc.).

Synthetic vitamins may not be efficiently absorbed due to improper binding with receptors inside the digestive tract (see visual examples in Good Food/Bad Food: A Little Book of Common Sense Nutrition). Additionally, the body may recognize synthetic vitamins as foreign and eliminate them in a process that creates more free radicals and further stresses internal organs.

Natural, whole-food vitamins are generally better absorbed as a result of improved binding with receptors inside the digestive tract.

Are There Other Toxins Besides Mycotoxin That Can Potentially Be Found in Processed Foods?

Yes, there are a variety of toxins besides mycotoxin that can end up on pet foods, both dry and moist. Some of the things to keep an eye out for are chemical preservatives, artificial colors, and moistening agents, including:

1. Butylated Hydroxyanisole (BHA) and Butylated Hydroxytoluene (BHT)

BHA and BHT are chemical preservatives added to oils (fats) that can be found in pet foods and treats.

BHA is included in California’s Office of Environmental Health Hazard Assessment list of Known Carcinogens and Reproductive Toxicants. The National Institute of Health reports that “dietary exposure to BHA caused benign and malignant tumors of the forestomach (papilloma and squamous-cell carcinoma) in rats of both sexes and in male mice and hamsters (IARC 1986, Masui et al. 1986)”.

BHT also a known carcinogen and causes kidney and liver damage in rats and has been banned as a human-food preservative in Australia, Japan, Romania, and Sweden. Yet, BHT has not been banned for people or pets in the United States.

My recommendation is that your pet’s food and treats contain either no preservatives or natural options like Vitamins C and E instead of chemical preservatives like BHA or BHT.

2. Ethoxyquin

Ethoxyquin is a chemical preservative which is illegal to use in human foods in the United States, yet it can still legally be added to our companion animals’ meals to prevent fat spoilage. Human safety data reports Ethoxyquin to be harmful when swallowed or when it comes into direct contact with skin.

Ethoxyquin can enter your pet’s food or treats in protein “meals,” such as fish meal. Manufacturers have to disclose that a toxin like Ethoxyquin has been added during the final production process. But if Ethoxyquin arrives at the final manufacturing site and is present in fish meal, then the manufacturer doesn’t have to disclose such information on the product label. Therefore, you may not even know that you are feeding Ethoxyquin to your pet, even after you have throughly read the label.

Such is why I suggest not feeding our pets diets that include protein or grain "meals" or "by products," and instead focusing on fresh, whole-food protein sources that lack chemical preservatives.

3. Carageenan

Carageenan is an ingredient found in canned pet foods; it is used to maintain consistency and moisture.

The International Agency for Research on Cancer (IRAC) reports that “sufficient evidence for the carcinogenicity of degraded carrageenan in animals to regard it as posing a carcinogenic risk to humans” exists.

As a result, it’s best to scrutinize your pet’s food and treat labels to ensure no carageenan enters the mouths of your canine or feline companions.

4. Food Dyes

Pets do not care about the color of their food. When approaching the bowl or plate, pets are instinctually drawn to food’s aroma. If the aroma is appealing, then a taste will be taken and a food’s flavor will keep the pet consuming that portion and coming back for more. Artificially coloring pet food just appeals to the pet owners who generally gravitate towards commercially-available, processed pet foods that simulate nature’s creations.

In humans, Blue 2, Red 40, and Yellow 5 and 6 contribute to hypersensitivity (allergic-type) reactions, behavior problems, and cancer. Caramel color contains 4-methylimidazole (4-MIE), a known animal carcinogen.

I recommend my patients don’t consume any foods or treats containing dyes. Instead, let nature provide the color and focus on the food’s aroma and flavor to appeal to your pet.

5. Meat and Bone Meal

Meat and bone meal can contain pentobarbital, a barbiturate anesthetic used to euthanize animals (confirmed through FDA testing of dog foods in 1998 and 2000). Additionally, meat and bone meal is one of the pet-food ingredients having a higher likelihood to contain heavy metals.

According to the Truth About Pet Food, ingredients listed as "meat and bone meal" could also be listed as “animal protein products (collective term), meat meal (if minerals are lower), by-product meal (if it doesn't meet constraints of MBM), meat & bone meal tankage (if blood is added back in).”

Avoid feeding your pet any products having meat and bone meal, or any of its versions having alternative names.

6. Propylene Glycol

Propylene Glycol (PG) is a humectant (moistening agent) found in certain soft dog treats (simulated meat versions) and dry dog foods having a crumbly texture.

PG is a chemical derivative of ethylene glycol (EG = antifreeze), which only requires small volumes to be consumed to cause life-threatening toxicity by damaging the kidneys. The "pet safe" antifreeze (Sierra, etc.) you may choose to put in your car is made from PG.

PG is touted to be non-toxic, tasteless, and non-absorbed by your dog, therefore it has a much higher margin for safety than EG. PG was previously used in moist and canned cat foods, but cats suffer toxic effects from PG consumption, like Heinz body anemia. As a result, the FDA banned PG’s inclusion in feline products.

Although PG is reported to be safe for your pet to eat, frequent ingestion of foods and treats having PG won’t improve your pet's overall health. Just have your pet’s food be moist as a result of the inherent water content or by adding your own filtered water, low-sodium broth, or other safe and natural hydration source.


Human-grade foods are less likely than feed-grade diets and treats to contain the above toxins that can be especially harmful for patients with cancer who may already have compromised digestive health as a result of their illness or as a side effect of treatment. Make sure to choose human-grade options for your pets during both times of wellness and illness.

Additionally, make it a part of your routine to reference the list of pet products that haven been recalled via FDA Recalls & Withdrawals

You can also sign up for Recall News alerts by registering with MypetMD and clicking the box to "Recieve Product Recall Alerts" under the Alerts tab. Just click the arrow at the top of the page to get started.  


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