9 Dog Food Ingredients to Avoid, and What to Look for Instead (Vet-Backed Guide)
You spend five minutes reading the back of a dog food bag and suddenly feel like you need a chemistry degree just to feed your dog breakfast. BHA, BHT, ethoxyquin, propylene glycol — what does any of this mean, and should you be worried?
Honestly? Some of it, yes. Not all dog food ingredients are created equal, and some of the stuff hiding in popular commercial brands has been linked to everything from allergies and digestive issues to serious long-term health problems. The frustrating part is that manufacturers often use technical names or bury these ingredients deep in the list, making them easy to miss.
This guide cuts through the noise. We'll show you exactly which ingredients to watch out for, why they're problematic, and — just as importantly — what good dog food actually looks like so you can make a confident choice at the store.
Why dog food ingredients matter more than you think
According to PetMD, the ingredients in your dog's food directly impact everything from their coat and energy levels to their long-term organ health. And here's something most pet owners don't realize: dog food labels list ingredients in descending order by weight. So the first five ingredients on that list make up the bulk of what your dog is actually eating every day.
A bag that lists "corn" or "wheat flour" as the first ingredient is essentially telling you your dog's primary nutrition source is a cheap filler — not protein. That's the starting point for understanding dog food labels, and it makes everything else much easier to decode.
The 9 dog food ingredients to avoid
1
BHA and BHT
High Risk
Also listed as: Butylated Hydroxyanisole, Butylated Hydroxytoluene
These are synthetic chemical preservatives added to oils and fats to extend shelf life. On the surface, that sounds harmless enough. The problem? According to the National Canine Cancer Foundation, BHA has been consistently linked to tumor growth in laboratory animals and is listed as a known carcinogen by California's Office of Environmental Health Hazard Assessment.
The FDA does technically allow BHA and BHT in pet food — but "legally permitted" and "safe for long-term daily consumption" are two very different things. Most premium dog food brands have already switched to natural alternatives.
Why it's in there
Cheap way to extend shelf life by months. Saves manufacturers money on production and storage.
2
Ethoxyquin
High Risk
Also used as: a pesticide in rubber production
This one is particularly concerning. Ethoxyquin is a chemical preservative commonly found in fish meal ingredients — and it's been banned from use in human food. Yet it still shows up in dog food regularly. What makes it even trickier is that manufacturers aren't legally required to list it on the label if it was added to an ingredient before arriving at their facility.
If your dog's food contains fish meal, look for a clear statement on the label or manufacturer's website confirming ethoxyquin-free sourcing. If you can't find that assurance, it's safer to assume it's present.
Why it's in there
Prevents fish meal from spoiling during storage and transport — a cost-saving measure for suppliers.
Important
When in doubt about preservatives, look for dog foods that use mixed tocopherols (Vitamin E) or rosemary extract as natural alternatives. These are safe, effective preservatives used by premium brands.
3
Artificial food dyes
High Risk
Look for: Red 40, Blue 1, Blue 2, Yellow 5, Yellow 6
Here's something that should make you pause: artificial colors in dog food exist entirely for your benefit — not your dog's. Dogs don't care if their kibble is brown or pink. These dyes are added purely to make the food look more appealing to humans picking it off a shelf.
The problem is that artificial dyes like Red 40 and Blue 2 have been linked to hyperactivity, extreme allergic reactions, and in some studies, carcinogenic compounds. There's simply no reason they should be in your dog's food. If you see them on the label, put it back.
Why it's in there
Makes food look visually appealing to human buyers. Has zero nutritional value for dogs.
4
Corn syrup and added sugars
High Risk
Also listed as: high fructose corn syrup, cane sugar, brown sugar, powdered sugar
Dogs don't need sugar in their diet. Full stop. Corn syrup is used as a cheap flavoring agent in many pet treats and some commercial dog foods — and it's highly addictive for dogs, which is exactly the problem. It keeps them coming back for more while slowly contributing to obesity, blood sugar spikes, diabetes, and dental decay.
There's also xylitol to watch out for — an artificial sweetener found in some human foods that occasionally makes its way into dog treats. According to KOHA Pet, xylitol is extremely toxic to dogs and can cause fatal hypoglycemia or liver failure even in small amounts. Always check peanut butter treats especially — some brands use it as a sweetener.
Why it's in there
Cheap flavoring that makes low-quality food more palatable. Creates repeat buyers by making dogs crave it.
5
Vague "meat meal" and unspecified by-products
Caution
Look for: "meat meal", "animal by-products", "poultry by-products" (unlabeled)
Not all meat meals are bad — "chicken meal" or "salmon meal" from an identified source is actually a concentrated, high-protein ingredient. The red flag is when the label just says "meat meal" or "animal by-products" with no species named. This vagueness means the source is unknown, and as several vets and pet nutritionists have pointed out, it can include low-quality, expired, or heavily processed animal scraps.
The rule here is simple: named protein sources are trustworthy. Unnamed ones aren't. "Chicken by-products" is clearer than "poultry by-products," which is clearer than just "meat."
Why it's in there
Significantly cheaper than named whole meats. Allows manufacturers to use whatever's cheapest at the time.
6
Rendered fat (unspecified)
Caution
Also listed as: "animal fat" with no source named
Like mystery meat, unspecified rendered fat is problematic because of where it comes from. It's sourced from unidentifiable animal materials and during the rendering process, it can become a breeding ground for mold, salmonella, and harmful bacteria. It also tends to concentrate toxins — including heavy metals — from whatever animals were used in its production.
Named fats like "chicken fat" or "salmon oil" are perfectly fine and actually beneficial. It's the generic "animal fat" listing that should make you pause.
Why it's in there
Enhances flavor cheaply. Sourced from the cheapest available animal materials with no quality control.
7
White flour and bleached wheat flour
Caution
Also listed as: wheat flour, white rice flour, bleached flour
These heavily processed starches are used as cheap binding agents and fillers. During the bleaching process, most of the original nutritional value is stripped away — leaving behind a simple carbohydrate that causes rapid blood sugar spikes. Over time, this contributes to weight gain, insulin resistance, and increases the risk of diabetes in dogs.
Whole grain alternatives like brown rice, oats, or sweet potato are far better choices — they offer fiber, slower energy release, and actual nutritional value.
Why it's in there
Extremely cheap filler that holds kibble together and adds bulk to make the bag look fuller.
8
Propylene glycol
Caution
Also known as: PG — a common ingredient in antifreeze
Propylene glycol is a moisture-retaining agent used in semi-moist dog foods and treats to keep them soft and chewy. It's already been banned from cat food by the FDA due to safety concerns — but it's still permitted in dog food. While it's considered less toxic for dogs than cats, many holistic vets recommend avoiding it entirely given its industrial origins.
You're most likely to encounter it in soft, chewy treats. Check the label before buying — it's not worth the risk when there are plenty of great treat options without it.
Why it's in there
Keeps semi-moist foods from drying out on shelves. Cheaper than using real, high-moisture ingredients.
9
Carrageenan
Caution
Derived from: red seaweed — common in wet/canned dog food
Carrageenan is a thickening agent extracted from red seaweed, commonly used in canned and wet dog foods to create that gel-like consistency. While it sounds natural enough, studies have linked it to stomach inflammation, digestive upset, and in some research, potential links to insulin problems and cancer.
If your dog regularly eats wet food and experiences unexplained digestive issues, carrageenan is worth investigating. Look for canned foods that use safer thickeners like agar or simply use broth-based recipes instead.
Why it's in there
Creates thick, appealing texture in wet food at very low cost. Widely available and cheap to source.
Pro Tip — How to read a dog food label in 60 seconds
Look at just the first five ingredients. If you see a named protein (chicken, beef, salmon) as the first ingredient — good sign. If the first ingredient is corn, wheat, or "meat meal" — walk away. Then quickly scan for BHA, BHT, artificial dyes, and corn syrup. That 60-second check will eliminate most of the worst options.
What good dog food actually looks like
Now that we've covered what to avoid, here's what you actually want to see on a dog food label:
Named protein first
Chicken, beef, salmon, lamb — as the very first ingredient
Whole grains or vegetables
Brown rice, sweet potato, oats — real carbs with fiber
Natural preservatives
Mixed tocopherols (Vit E), rosemary extract — safe and effective
Named healthy fats
Chicken fat, salmon oil, flaxseed — great for coat and joints
Short ingredient list
Fewer ingredients generally means less room to hide fillers
AAFCO statement
"Complete and balanced" per AAFCO means it meets minimum nutrition standards
Quick checklist — before you buy any dog food
Run through this at the store:
- ✓Is the first ingredient a named protein (chicken, beef, fish)?
- ✓Does it have an AAFCO "complete and balanced" statement?
- ✓Are the preservatives natural (tocopherols, rosemary)?
- ✓Is the ingredient list reasonably short and readable?
- ✗Does it contain BHA, BHT, or ethoxyquin?
- ✗Do you see artificial dyes (Red 40, Blue 1, Yellow 5)?
- ✗Is corn syrup or any added sugar listed?
- ✗Does it say "meat meal" or "animal by-products" with no species?
Frequently asked questions
What is the number one ingredient to avoid in dog food?
BHA (Butylated Hydroxyanisole) is widely considered the most concerning ingredient in commercial dog food. It's a synthetic preservative linked to cancer in animal studies and listed as a known carcinogen by several health organizations — yet it's still legally permitted in pet food. If one ingredient should be a dealbreaker, this is it.
Is corn bad for dogs in dog food?
Corn itself isn't toxic to dogs, but it's a low-value ingredient when used as a primary filler. Whole corn provides very little digestible nutrition for dogs, and refined corn products like corn syrup or corn flour can spike blood sugar. The issue isn't corn as an occasional ingredient — it's corn appearing as the first or second ingredient in a formula that should be protein-first.
Are "by-products" in dog food always bad?
Not necessarily. Named by-products like "chicken liver" or "chicken hearts" are actually nutrient-dense organ meats that can be very healthy. The problem is generic labels like "animal by-products" with no species named — those are impossible to evaluate for quality. When in doubt, stick to foods where every protein source is clearly identified.
How do I know if my dog's food contains ethoxyquin?
This is tricky because manufacturers aren't required to list it if it was added before the ingredient arrived at their facility. The safest approach: if the food contains fish meal, contact the manufacturer directly or look for a clear "ethoxyquin-free" statement on their website or label. Premium brands like Orijen, Instinct, and Wellness CORE have made public commitments to avoid it.
What are the healthiest dog food brands in 2025?
Brands consistently praised by veterinary nutritionists for clean ingredients include Orijen, Acana, Instinct, Wellness CORE, and fresh food options like The Farmer's Dog and NomNomNow. That said, the best food for your dog depends on their age, breed, health conditions, and activity level — always consult your vet before making a major food change.
