8 Bad Dog Food Ingredients

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8 Bad Dog Food Ingredients

In this article you can find some ingredients you should avoid found on your dog’s food label.

1. Corn, Corn Meal, or Corn Gluten Meal

The gluten in corn is used as a lower quality protein source in dog foods.

Corn protein is not a complete protein font and must be balanced with animal origin proteins to make a correct amino acid profile for dogs.

bad food ingredients
Regrettably corn is often abused as the single most plentiful ingredient in numerous dog foods, contributing to lots of diseases associated with high carbohydrate diets, such as:

  • Obesity
  • Chronic inflammation
  • Hyperactivity
  • Change in mental behavior
The quality of the corn is also an issue as a lot of dog foods employ little quality corn containing toxins (e.g. mycotoxins) and mold which cause damage to a dog’s liver and kidneys.

2. Wheat

Wheat is an additional ingredient found in great quantity in various dog foods.

The recurring and constant exposure of wheat to dog gastrointestinal system has resulted in allergies and intolerances to wheat and wheat gluten.

Wheat gluten is also used as a cheap protein source in dog foods.

3. Soy

Soy is one of the most widespread allergens in dogs.

It is normally used in dog food as a low-priced substitute for meat protein.

As an extra problem is that an estimated 89% of soy and 61% of corn crops are genetically modified.

Genetically modified organisms or foods are shown to negatively affect dog’s health.

4. Powdered Cellulose, Dried Beet Pulp, Rice Hulls

Cellulose or Powdered Cellulose is used as protective material.

Cellulose is usually used in attic insulation.

So you should feed your dog a food not containing cellulose.

Dried Beet Pulp is the left over residue from production of table sugar.

Table sugar is often used to promote interest in the nasty mixture pet food manufacturers make.

There is no motive for added sugar to be placed in pet food.

Rice Hulls are the rigid protecting coverings of grains of rice.

Rice hulls can be used in the production of building material, fertilizers, insulation materials, or fuels.

5. By-Products

This could include:

  • Chicken
  • Lamb
  • Beef
  • Fish
  • Turkey
“By products” are the internal remains of an animal, excluding the muscle meat.

Frequently, this will include diseased tissues, organs and tumors.

By-Products are left over wastes from human food industry.

By-Products come in two types:

  • Named (e.g. “chicken by-products” and “pork by-products”)
  • Un-named
The Association of American Feed Control Officials defines:

  • “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.”
  • “Meat by-products consist of 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 stomachs and intestines freed of their contents. It does not include hair, horns, teeth and hooves.”
By-products are not categorized as meat; in many dog foods the exclusive use of by-products creates a food that does not include actual meat content, all to reduce costs.

6. Animal Fat

Animal fat consists mainly of glyceride esters of fatty acids and contains no additions of free fatty acids.

Animal fat includes meat sources from the “4-D” class – defined as food animals that have been rejected for human consumption because they were presented to the meat packing plant as “Dead, Dying, Diseased or disabled.”

7. Meat Meal

The Association of American Feed Control Officials defines:

  • “Meat Meal consists of the rendered product from mammal tissues, exclusive of blood, hair, hoof, horn, hide trimmings, manure, stomach and rumen contents except in such amounts as may occur unavoidably in good processing practices.”
Again, a meat meal does not represent actual meat content.

8. Chemical Preservatives

These potent chemicals are utilized as preservatives and to avoid rancidization of fats, such as:

 BHA (Butylated Hydroxyanisole) and BHT (Butylated Hydroxytoluene)

These are petroleum derived preservatives employed in food and hygiene products.

BHT has been forbidden from use in baby products in the United States and both BHA and BHT are banned totally from use in human products in many countries Pets do not receive the same protection.


It’s applied as a food preservative and a pesticide. In pet foods it is typically found in meat and fish based ingredients.

Veterinarians began perceiving that ethoxyquin is often linked with the development of:

  • Kidney and liver damage
  • Cancer (liver, spleen, stomach, skin)
  • Immune deficiency syndrome
  • Blindness
  • Leukemia
Propyl Gallate

It’s used in foods, cosmetics, hair products, adhesives, and lubricants

Propylene glycol

It is used in many dog foods and treats as a flavor enhancer due to its sugary taste.

It is a questionable ingredient in pet food for the following reasons:

  • It is found in anti-freeze
  • This product helps to reduce moisture and prevent bacteria growth, affecting the health of dog’s  intestinal flora
  • Some dogs may develop intestinal cancer or intestinal blockage
Artificial Colors

Colored kibbles are not for the profit of the dog, they are in fact to make them more attractive to you.

Artificial colors are synthetic chemical dyes that have no place in dog food

It is particularly important for you to read and comprehend your dog’s food label, do your own research, but always do so as an informed consumer.

We hope this information helps you in some way.

Things to remember

What should you look for in dog foods?

  • Meat, meat and more meat products
  • Meat and fat products that are identified by species
  • Look for good quality whole grains
  • Whole fruits and vegetables are appreciated
  • Organic grains are very good where grains must be used, but they are no substitute for meat content
What should I avoid in dog foods?

  • Foods containing any form of by-products
  • Artificial colors, flavors, sweeteners or preservatives: BHT, BHA, Ethoxyquin, Propyl Gallate, among others.
  • Meats and fats that are not identified by species. These could literally be anything.
  • Avoid those products that make abundant use of grain fragments
  • Fish products, may contain artificial preservatives that are not disclosed on the ingredient list; if they are not added by the manufacturer. Thus you should look for assurances by manufacturers using ocean fish products that their foods do NOT contain any artificial preservatives.
In the following weeks you can find reviews about some dog foods in our Dog Food Selector.

About the Author:

Hi! I'm Dora Mancha, DVM. I am graduated for the Veterinary Medicine Faculty of Lisbon (2009). My degree is recognized by the American Veterinary Medical Association (AVMA). I completed my degree in Veterinary Medicine in July, 2009. Over the first years as a veterinarian my work was closely related to the animal health field. I have gained some average experience having worked in Barcelona University (UAB) Equine Hospital and by working with veterinarians in Portugal. In addition, in 2009 - 2010 I was in Madrid at the University Alfonso X el Sábio doing an internship in the equine service. I am also very interested in small animal medicine and surgery. In fact I worked in several small animals clinics in Portugal improving my knowledge about small animal behavior and health. Dogs always have been present in my life, since I was a child. At the present moment I have four dogs a Labrador, a Epagnheul Breton, a Whippet and a mixed breed dog.


  1. Dorothy April 26, 2015 at 9:26 pm - Reply

    I’d like to get on your mailing list if you have one. I just saw this post kn FB and it’s obviously been quite a while ago. I’m interested in knowing what dog foods are recommended as good.

  2. Lyn Arnold October 1, 2015 at 9:41 pm - Reply

    Very interesting. It’s time the consumer knew this. Thank you.

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