Updated By Ryan Walker 4 min read

Dog Food Ingredients You Should Avoid and Why

Verified by Joe Ghafari, CNC, CPT, CES
Dog Food Ingredients You Should Avoid and Why - Good Bark
Whole ingredients you can picture are the starting point for a cleaner label.
In this article

What Makes a Dog Food Ingredient Worth Avoiding?

Some ingredients are genuinely dangerous and should be cut entirely. Others are low-quality fillers that simply displace better nutrition. An ingredient makes the avoid list if it's acutely toxic, linked to chronic health issues, or a filler replacing real food.

Ingredient labels are written to comply with regulations, not to be transparent. Water-heavy meats rank high on the list even when actual protein is low. Companies also split ingredients, listing corn as "corn flour" and "corn starch" separately so each appears lower. Knowing what to look for cuts through this.

Artificial Preservatives: BHA, BHT, and Ethoxyquin

BHA and BHT are synthetic antioxidants that extend shelf life in fats. The National Toxicology Program has listed BHA as reasonably anticipated to be a human carcinogen. Animal studies show BHT can affect liver function at high doses [citation:3]. Both are legal in pet food, but their presence signals how a product is made.

Ethoxyquin is a chemical preservative originally developed as a pesticide and rubber hardener. The FDA asked manufacturers to reduce its use in the 1990s, but it's still legal and still appears in some formulas. Veterinary nutritionists continue to raise concerns about its cumulative effects [citation:2].

Vitamin E (tocopherols) and vitamin C (ascorbic acid) preserve fats just as effectively. Synthetic preservatives exist out of cost and convention, not necessity.

Artificial Colors and Flavors

Food dyes like Red 40, Yellow 5, and Yellow 6 serve one purpose in pet food, making the product look appealing to you, the buyer. Your dog doesn't care what color their kibble is. Some artificial colors have been studied for links to hyperactivity and allergic reactions, and the FDA continues to review several [citation:1].

"Natural flavor" without a source is a different problem. It can mean rendering by-products, chemical compounds, or low-grade extracts. If a food is made with chicken, sweet potato, or peanut butter, it doesn't need a mystery flavor booster.

Xylitol: The One That's Actually Dangerous

Xylitol is a sugar alcohol used as a sweetener in many human foods, including some peanut butters. Even small amounts trigger a rapid insulin release in dogs, causing hypoglycemia. Larger doses have caused liver failure. The ASPCA Animal Poison Control Center lists xylitol as one of the most common causes of pet poisoning [citation:4].

This is acute, not theoretical. A dog can be in serious trouble in hours.

If you feed your dog peanut butter as a treat, in a Kong, or as a pill pocket, check the label every time you buy a new jar. Brands change their formulas. We wrote a dedicated guide on what to look for in peanut butter for dogs if you want the full breakdown.

Corn Syrup and Added Sugars

Commercial dog foods sometimes include corn syrup, cane molasses, or other sweeteners to boost palatability. Added sugar contributes to weight gain, dental decay, and blood sugar dysregulation over time.

Sugar masks low ingredient quality. If a food needs sweetener to get a dog to eat it, the actual ingredients likely aren't very good.

Scan labels for corn syrup, high fructose corn syrup, cane sugar, molasses as a sweetener, and dextrose. A treat built around a named whole food doesn't need any of them.

Vague "Meat Meals" and By-Products from Unknown Sources

"Meat meal" and "poultry meal" sound like protein. The quality varies widely and the source is unspecified. Rendered meal from unnamed sources can include 4-D livestock (dead, dying, diseased, or disabled), which is legal in US pet food.

Named meal is different. "Chicken meal" or "salmon meal" must come from that specific animal per AAFCO standards. These are concentrated protein sources, so they rank high on the label. Unnamed meal is the problem.

The same applies to "animal fat" versus "chicken fat" or "salmon oil." Named sources have a known nutritional profile. "Animal fat" is a catch-all.

If you can't picture what an ingredient is, that's a flag.

Fillers: Corn, Wheat, Soy, and Cheap Starches

Why Fillers End Up in Pet Food

Corn, wheat, and soy are inexpensive and calorie-dense. They bulk up a formula and hit minimum nutrient percentages on paper. Dogs metabolize carbohydrates fine. The real issue is displacement, when a significant portion of a food is cheap filler, there's less room for quality protein and whole foods.

Corn and soy are also common food allergens for dogs, alongside beef, dairy, and wheat [citation:5]. A dog with chronic itching, ear infections, or digestive upset is often reacting to something in the diet, and fillers are worth investigating first.

What the Ingredient List Actually Tells You

AAFCO requires ingredients to be listed by pre-cooking weight. A food with "chicken" first and "corn" second might be mostly corn after water cooks out. Two or three corn derivatives (corn flour, corn starch, corn gluten meal) each appear lower while collectively dominating the formula.

Short ingredient lists with named items are harder to manipulate.

A Quick Reference: Ingredients to Scan For

Here's what to scan for on a label.

  • BHA / BHT / ethoxyquin: synthetic preservatives with no nutritional value. Natural alternatives exist.
  • Artificial colors (Red 40, Yellow 5, Yellow 6, Blue 2): no benefit to your dog. There for you, not them.
  • Xylitol: avoid entirely. Non-negotiable.
  • Corn syrup / cane sugar / dextrose: added sweeteners that mask low-quality ingredients.
  • Meat meal / poultry meal / animal fat: fine if named (chicken meal, salmon oil). A red flag if unnamed.
  • Corn / wheat / soy (especially listed multiple times): common fillers and allergens.
  • Propylene glycol: a humectant used in semi-moist foods that has been associated with red blood cell damage in cats and is under review for dogs.
  • Carrageenan: a thickener derived from seaweed used in wet foods, with ongoing discussion in veterinary nutrition circles about its effects on gut inflammation.

How Good Bark Treats Are Formulated Instead

Good Bark treats use 9 simple, human-grade ingredients per flavor. No corn, wheat, soy, artificial preservatives, or fillers. The Peanut Butter & Blueberry and Sweet Potato & Honey formulas are built from whole foods you recognize: oat flour, real fruit, real vegetables, natural binders. [product:1]

Each treat breaks into 3 to 5 pieces, making it easy to use as a training reward without overfeeding. A short ingredient list means nowhere for hidden junk to hide.

For a deeper breakdown on evaluating treat labels, our guide on what makes a dog treat actually healthy walks through the full framework.

A short list of named, whole ingredients you can picture is almost always a better sign than a long list of things you have to look up. [product:2]

Frequently asked questions

What are the most harmful ingredients in dog food?

The most acutely harmful ingredient is xylitol, a sweetener that can cause rapid blood sugar drops and liver damage in dogs. Synthetic preservatives like BHA, BHT, and ethoxyquin, artificial colors, and unnamed meat meals are also ingredients many veterinary nutritionists recommend avoiding. The safest approach is a short ingredient list made from named, whole-food sources.

Is corn bad for dogs in dog food?

Corn itself isn't toxic to dogs, but it's a common filler that displaces more nutritious ingredients and is one of the more frequent food allergens for dogs. It often appears in multiple forms on the same label (corn flour, corn starch, corn gluten meal), which can make its total proportion hard to assess.

What preservatives should I avoid in dog food?

Avoid BHA, BHT, and ethoxyquin. These are synthetic preservatives used to extend shelf life in fats. Natural preservatives like mixed tocopherols (vitamin E) and ascorbic acid (vitamin C) accomplish the same thing without the associated concerns.

Is xylitol in dog food a real risk?

Yes. Xylitol is one of the most common causes of pet poisoning according to the ASPCA Animal Poison Control Center. It's rarely used in commercial dog food itself, but it does appear in some peanut butters and treats marketed for human use that owners give their dogs. Check every jar of peanut butter before feeding it to your dog.

What does "meat meal" mean on a dog food label?

Meat meal is rendered, dried protein from animal sources. Named meat meal (like "chicken meal" or "salmon meal") must come from that specific animal per AAFCO standards and can be a legitimate concentrated protein source. Unnamed "meat meal" or "poultry meal" has no specified source and is generally considered lower quality.

Are fillers in dog food actually bad for dogs?

Fillers like corn, wheat, and soy aren't toxic, but they take up space that could be filled by higher-quality protein and whole-food nutrition. They're also among the more common dietary allergens for dogs. A food where fillers dominate the first several ingredients typically provides less nutritional density than one built around named meats and whole foods.

What should the first ingredient in dog food be?

Ideally, a named protein source — chicken, beef, salmon, turkey. A named protein first on the label indicates the food is built around animal protein rather than grain or filler. Be aware that named meats are listed by pre-cooking weight, so a food with chicken first and corn second could still be largely corn-based after moisture is removed.

How do I read a dog food ingredient label?

Read from top to bottom. Ingredients are listed by weight before processing. Look for named, recognizable ingredients in the top five slots. Watch for filler ingredients listed multiple times under different names (corn flour and corn starch, for example). A short list with no synthetic preservatives, no artificial colors, and no unnamed meat sources is a reliable positive signal.

References

  1. 1. ASPCA Animal Poison Control Center American Society for the Prevention of Cruelty to Animals
  2. 2. FDA, Pet Food U.S. Food and Drug Administration
  3. 3. National Toxicology Program, BHA Report U.S. Department of Health and Human Services, National Toxicology Program

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