24 Bad Ingredients in Dog Food | Bad Dog Food Ingredients

23 Minute Read
 | Amy Dyck
Updated April 17, 2021

You want the best food for your dog, but that's not easy when marketing and economics get in the way of what's healthful for your pet. Learn what dog food ingredients to avoid in dog food so that you can feed your pet the high quality they deserve. 

You can't trust the brands themselves, as pet food companies can use tricks to make their food appear better than it actually is. The package and the commercials can be misleading, but the ingredient list offers a more truthful look at what's actually in your dog's food.


These bad ingredients in dog food are some of the worst offenders in pet food. While all of these ingredients are legal to put in dog food in Canada, they've been outlawed in many countries and are just not worth the risk.

Check your dog food ingredient label to make sure it's not harbouring one of these common but potentially harmful dog food ingredients. You might even want to check your food, as some of these ingredients can be found in people's food as well. Instead, choose one of the healthy alternatives suggested.

Watch out for these 24 Bad Ingredients in Your Dog's Food:



These chemical preservatives are used to preserve fats in human and pet foods. Banned in some countries, BHA and BHT are approved for food use in small quantities in Canada, the US, and Europe. Studies have been inconclusive so far, but BHA and BHT have been linked to child hyperactivity and even cancer.

However, there is also promising research that they can be used to help cure herpes and even AIDS. The problem is nothing is for sure. Until more research is available, avoid these potentially harmful additives whenever you can. 

Human foods BHA and BHT are found in include: dry cereals, butter, beer, margarine, chewing gum, and other processed food products. 


Healthy Alternative: Natural Preservatives or Canned Food

There are plenty of natural preservatives used in pet foods, such as:

  • Vitamin C (ascorbic acid)
  • Vitamin E (mixed tocopherols)
  • Rosemary
While they are not as effective for as long as artificial preservatives are at preventing fat rancidity (so they tend to have shorter expiry dates), they're a safer choice.

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If you want to avoid preservatives completely, go with canned dog food. One of the benefits of canned dog food is that the canning process eliminates the need for chemical preservation. 


2. White Flour


White flour is a simple carbohydrate with most (if not all) of its nutrition stripped. The problem with white flour is that it causes a spike and then a drop in blood sugar, causing you (or your dog) to be hungry again soon after consuming it.

Overconsumption of white flour can lead to weight gain, obesity, and diabetes.


Healthy Alternative: Whole Grains or Grain-Free

White flour is not necessary for your diet or your pet’s – choose nutritious, novel whole grains instead. Whole grains like quinoa, oats, or brown rice are all great alternatives. You can also look for foods that use legumes, sweet potatoes, or other high-fibre nutritious veggies. 


3. Meat and Meat Meal

Meat is healthy for your pet. It should comprise most of your dog's diet. However, if you see unnamed “meat”, “meat meal”, or “meat and bone meal”, you know that your pet is getting the worst source of meat he could in processed food.

Meat is another one of those non-descript food items that will keep cropping up in this list of worst dog food ingredients.

When manufacturers include “anything goes”, non-descript terms, such as "meat", it is always a guess at what's in them. These ingredients bad for dogs are always the leftovers, and the only guarantee is that there is no guarantee of any standard of quality.

The ingredients can be diseased, from dead animals, from expired meat sections in grocery stores (complete with plastic packaging), or even include tumours – you name it.

Once this Frankenstein concoction is compiled, it is heated extensively to remove any pathogens that might be there (they most definitely are). This process also removes most nutrients that might be in these questionable ingredients.

The result is a difficult-to-digest, nutritionally-void filler that boosts the protein percentage on your dog food bag but adds little usable protein for your pet.


Healthy Alternative: Named Meats and Meat Meals

Look for real meats you can recognize, such as whole deboned chicken, turkey, lamb, beef, or salmon, or meals of these meats. These ingredients are likely processed less and contain more natural nutrients and usable protein. 

To help you find the healthiest foods for your pooch, check out The Best Kind of Protein for Dogs.


4. Artificial Colours


Artificial colours make things look more visually appealing. However, artificial colours have been linked to hyperactivity as well as several biochemical processes within the body.

The only reason artificial colours are used in any food is to make the food look better to you.

It's completely unnecessary for people and pets. And there's no reason to use artificial colouring in food. There are many naturally-derived colours available to manufacturers.

Artificial colours can be in anything, even fruit – but particularly processed foods. 


Healthy Alternative: Embrace Natural Colours

Your dog's natural food colour may not be that visually appealing, but you might just notice the difference quality makes in his skin and coat, health, and vitality. 


5. MSG

MSG (monosodium glutamate) is prevalent in many prepared foods. But as common as the flavour enhancer is, MSG can cause trouble for humans and pets alike.

In pet foods (as well as human foods), it is used to make up for the lack of flavour in low-quality ingredients. Aside from being nutritionally unnecessary, MSG also happens to be a very common allergen in humans and pets. Why risk it?

While MSG by law doesn't have to appear on pet food ingredient labels, you can often find it in these ambiguous ingredients:

    • hydrolyzed protein
    • protein isolate
    • texturized protein
    • natural flavours (like chicken flavour)
    • autolyzed yeast
    • hydrolyzed yeast
    • yeast extracts
    • soy extracts or concentrate
    • sodium caseinate
    • calcium caseinate
    • monopotassium glutamate
    • glutamate or glutanic acid
    • disodium inosinate or guanylate


Healthy Alternative: Foods High in Named Meat Protein

MSG is a cheap, non-nutritive, unnatural flavour source – why not rely on real food ingredients to add flavour instead of fake alternatives? Rich inclusion of chicken, beef, or pork in your pet's food would eliminate the need for flavour enhancers.


6. Gluten

There aren't many ingredients that get as much buzz in the press as gluten does these days. While many people are avoiding gluten to improve their digestion and even lose weight, your dog's reasons for avoiding gluten might be even more compelling.

Gluten, found in grains, is not a natural food for dogs or cats to consume. In dog food, gluten can be found in any gluten-containing grain, such as wheat or barley.

Also, wheat gluten can often be found as an ingredient on their own, used as binders to form the kibble shape and texture. 

Dogs are considerably more receptive to gluten-containing grains than cats are, but many still develop allergies and suffer from digestive distress due to the unnecessarily high quantities of grains in the standard processed kibble diet.

Stinky ears and chronic ear infections, itching, and hot spots are all common signs of gluten sensitivity or allergy in your pet.


Healthy Alternative: Go Grain-Free

Is your pet suffering? You may want to go gluten-free. Grain-free dog foods include vegetable sources of carbohydrates, such as sweet potatoes, or stick to gluten-free grains like oats or buckwheat.


7. Corn Syrup


We all know that corn syrup is bad for our health. But did you know this cheap, sweeter-than-sugar sweetener can be food in pet food and treats, too? Corn syrup, much like refined sugar, causes spikes in blood sugar and contributes to weight gain, obesity, and diabetes. It's also addictive, and the more your dog eats, the more he'll develop a taste for all things sugary sweet. 

In human foods as well as pet foods and treats, sugar and sweeteners are plentiful.


Healthy Alternative: Skip It

Avoid sugar in all its forms: molasses, caramel, dextrose, fructose, glucose, cane molasses, or maple syrup. If your dog's food has enough quality meat protein in it, your dog won't need any flavour enhancement.  


8. Farmed Salmon

Salmon is healthy for both you and your pets, but the wrong salmon can include harmful toxins. Farmed salmon, salmon meal, and salmon oil in your pet’s food can add mercury, PCBs, and other fat-soluble toxins to the diet.

According to a farmed salmon brochure by David Suzuki and the cited Journal of Nutrition (2005), levels of 13 fat-soluble pollutants are almost 10 times higher in farmed salmon than in wild salmon. The cancer rate from consuming farmed fish can be up to 3 times that of wild fish. 


Pet-Tek Salmon Oil


Healthy Alternative: Wild-Caught Salmon

Look for sustainable, wild-caught salmon for lower levels of pollutants and reduced cancer risk. It should be advertised on the pet food bag as wild-caught. Note there are no commercial Atlantic salmon fisheries, so if the salmon is listed as Atlantic, it's farmed. 


9. Xylitol and Other Sugar Alcohols


Sugar substitutes can be deadly for pets, and new research shows that they aren't doing you any favours, either. While sugar alcohols (such as sorbitol, maltitol, and xylitol, among others) may have little or no calories, they can still have an effect on blood sugar.

Xylitol causes a surge in your pet's blood sugar and then a subsequent drop, which can result in hyperglycemia. Other complications can include seizures, liver failure, and even death.

While only xylitol is toxic to dogs, other sugar substitutes do nothing for your pet nutritionally. Their inclusion in the diet only feeds your dog's sweet tooth, which can make him crave sugar.

And truthfully, sugar substitutes will do the same for you.

Recent studies link high sugar substitute intake with high blood sugar, a precursor to Type 2 Diabetes in humans, due to how these sugar substitutes alter normal gut flora. You and your pet would be better off enjoying whole food treats, such as fresh fruits and veggies.


Healthy Alternative: Skip It

Sugar substitutes are alternatives, but they're questionably healthy. If your dog doesn't need it at all, there's no need to include it. Just choose a dog food with healthy ingredients, including naturally-sweetened fruits and vegetables and hearty-named meats such as chicken.


10. Nitrites or Nitrates (Sodium Nitrite)

Nitrites and nitrates, commonly found in prepared meats such as sausages, bacon, ham, hot dogs, and deli meats, are a preservative used to extend the shelf life of meat products.

Prepared meats are high-fat, high-salt items that can be occasional treats for you (think: once a week or less) but are better to avoid feeding your pet. However, it's not just human foods you have to be concerned about.

Sodium nitrite is an approved preservative in pet foods and can be toxic in high doses by causing a blood disorder called methemoglobin.

Its accumulation over time in the system has also been linked to cancer, especially when combined with added ascorbic acid (Vitamin C) and alpha-tocopherol (Vitamin E), which are common natural vitamin sources.


Healthy Alternative: Go Canned or Skip It

The process of canning dog food preserves, eliminating the need for adding chemical preservatives to food. Supplementing canned food can be beneficial by reducing your pet's exposure to preservatives, even if you feed dry food some of the time.

Whenever possible, choose natural preservatives (such as mixed tocopherols, ascorbic acid, and rosemary) and make sure nitrites or nitrates are not in your pet food's ingredient list. 


11. Soy


Few ingredients are as controversial as soy in both human and pet foods. But, while soy may have some benefits for you, there are a few things it does for pets.

The truth is, grain and vegetable-based protein sources are just not as useful to pets as their meat protein counterparts.

The reduced bioavailability of plant-based proteins, or the ability of your dog's body to process and use the proteins and nutrients, makes these proteins less usable for energy and body processes from immune response to muscle maintenance to metabolism.

While soy is one of those few plant protein sources that actually contain all necessary amino acids, it is often difficult for pets to digest, causing bloat and gas. A cheap ingredient, it is plentiful in many low-quality pet foods as a protein percentage booster.

A common allergen, soy is best to avoid in dog food altogether if you have pets.


Healthy Alternative: Choose Meats

The best proteins for your pet are meat-based proteins. Eggs and named meats or meat meals have high bioavailability for dogs and cats. These sources of protein have complete amino acid profiles for both dogs and cats and are easy for pets to digest. 


12. Sodium Tripolyphosphate (STPP)

While you may not recognize it by its name, sodium tripolyphosphate is the active ingredient in many detergents, as its main use is softening water. So why is it in your dog food? Good question. Sodium tripolyphosphate works as a preservative in your pet's food. 

According to a fact sheet by the Food & Water Watch, sodium tripolyphosphate can be harmful if inhaled and is a skin irritant (MSDS). While it is GRAS (generally regarded as safe) to eat, the National Institute for Occupational Safety and Health problems (a division of the CDC) suspects it may be a neurotoxin.

And the U.S. Environmental Protection Agency (EPA) recognizes sodium tripolyphosphate as an insecticide, fungicide and rodenticide. Let's leave this unnecessary, non-nutritive ingredient out of our dog food. 

Watch for STPP in your fish, too. It's used as a soak and can be found in scallops, shrimp, and flaky, filleted fish.


Healthy Alternative: Go Natural

Go for natural preservatives, such as rosemary extract, instead. Rosemary is not recommended for dogs that have any type of seizure disorder, so always check with your vet if your dog has a health condition that might be affected by these ingredients. 


13. Salt


Salt is necessary for both human and canine nutrition. However, too much salt is harmful to both us and our pets. Salt is usually found in sufficient quantities in your pet’s food without adding it directly.

Manufacturers add salt to pet food for flavour and to encourage drinking (although salt consumption can lead to dehydration). High levels of salt can contribute to high blood pressure and other suspected health conditions, including stomach cancer, stroke, and cardiovascular disease.

Pet food is required to include less than 1% salt in a complete and balanced diet. When a high-quality diet is fed in appropriate portions your dog should get all the salt they need daily.

Try to avoid feeding treats and human foods that are high in salt.


Healthy Alternative: Skip It

Once again, if your pet food contains plenty of real, quality meat, your dog or cat won't need any added flavour enhancers. 

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14. Rendered Fat

Also called animal fat, rendered fat is a very low-quality ingredient in dog foods. While fats from animals are healthy in moderation, unamed “animal fat” or “poultry fat” comes from unidentified animals, which may not be from the highest quality sourced. There is simply no way to tell.

It is often rancid, and its inclusion in your pet's food means that other questionable ingredients, such as non-descript flavours will be added to cover up the taste.

The other problem with this low-quality fat is the toxin load. Many toxins are stored in animal fat. Low-quality fats contain more fat-soluble toxins than more desirable descriptive fats, such as “chicken fat".


Healthy Alternative: Choose Fats from Named Sources

Make sure all the ingredients listed as fats or oils in your pet's food come from named, known sources. Avoid non-descript terms such as poultry fat, animal fat, vegetable oil, and fish oil, favouring named ingredients such as salmon oil, chicken fat, beef fat, pork fat, and coconut oil instead.


15. Propylene Glycol


Does this one sound familiar? Yes, it's a common ingredient in newer antifreeze. While not as toxic as its relative, ethylene glycol, FDA-approved propylene glycol is still of questionable safety.

In fact, it's been banned in many countries or is at least tolerated at much lower levels. Used as a humectant or to keep moisture in semi-moist foods, propylene glycol may be toxic in large amounts.

While it can be safely metabolized by your dog's liver into safe compounds and manufacturers assure us of its safety for use in food, propylene glycol has been found to be toxic to cats, causing Heinz body anemia.

So much so that propylene glycol is not allowed as an ingredient in cat food. You're better off saying no to propylene glycol, especially if you have cats in the house.

Drink cola? You'll find propylene glycol in there and many other common processed products such as beer, margarine, cake mix, and flavoured coffee.


Healthy Alternative: Avoid Semi-Moist Foods

Avoid those foods marketed as semi-moist. Choose canned or even dry instead to avoid this troublesome ingredient.


16. Vegetable Oil


Vegetables and fats; Two things your pet needs, right? Yes, but not in the form of vegetable oil, which is primarily composed of cheap corn and soybean oils.

Vegetable oil, like most non-specific ingredients bad for dogs, often contains high levels of omega 6 fatty acids. While these fatty acids are essential, pets eating a processed commercial diet often have way more of these EFAs (essential fatty acids) than is healthy.

Since omega 6's are responsible for inflammation, and omega 6 fatty acids are already heavily represented in most commercial diets, these excess fats can exacerbate arthritis, hip and joint problems, and many other medical conditions.


Healthy Alternative: Descript Fats

Look for healthy sources of fats that include high levels of omega 3 fatty acids, such as named fish oils (salmon), olive oil, or flaxseed oil. Healthier fats to look for include chicken fat and pork fat. Avoid tallow and lard, which are very cheap and heavily processed bad dog food ingredients that are low in nutrition.


17. Animal By-Products

Another non-descript protein source. Animal by-products are all the remnants of the animal carcass after all the meat and bones have been removed (probably to be used in the meat and bone meal above).

What does that mean exactly? Animal by-products are not all bad. They are legally required to be free of feathers, hooves, hair, hide, beaks, and any other non-edible parts of the animal. Organ meats are a type of animal by-product and are a healthy ingredient in pet food.

The issue with animal by-products, and the reason they made our list, is that they are nutritionally inconsistent. Unnamed animal by-products can be so heavily processed that little to no nutrition is left for the pet.

Additionally, by-products are often cheaply sourced, so you'll never know if the by-product used in your pet's diet is actually providing valuable nutrition. 

If you want to stick to healthy animal by-products, look for foods that use named animal parts, like dog heart, liver, or kidney, as opposed to unnamed and questionable animal by-products.  


Healthy Alternative: Choose Meats

Once again, why choose anything else when what your dog and cat need most is real meat? Raw diets are a great option for any pet owner looking to ensure high levels of nutrients rich and minimally processed real meat sources. 


18. Cellulose


This recent additive in food is being used more and more. Cellulose is plant or wood fibres. What is wrong with cellulose in dog food?

Fibre is about all the nutrition cellulose provides. Cellulose is indigestible. While fibre is beneficial to digestion, if you and your pet are eating a balanced diet with whole foods – including fruits, veggies, and unrefined grains – you should be getting all the fibre you need.

The real reason cellulose is being added to foods is that is a cheap binder, emulsifier, and an anti-caking agent, and can be used in diet foods to resemble fats. Oh, and it's dirt cheap. It literally grows on trees.

Cellulose can be found in your pet’s food, as well as many fast foods, diet foods, processed meat and cheese products, granola and “health” bars, processed breakfast foods, and even ice cream. The list goes on.


Healthy Alternative: Skip It

There isn't really an alternative for cellulose in dog food, it's nothing more than a filler, something used to create texture that should already be there if quality ingredients are being used. 


19. Brewers Rice

Brewers rice is a common carbohydrate source in low-quality dog foods, but it's also an ingredient you should avoid. While it may sound like whole grain, brewer's rice most definitely is not.

Brewers rice is not even whole white rice, it is fragments of rice that are left over after white rice has been processed. Brewers rice isn't toxic and does provide trace amounts of a few minerals and digestible carbs. So why is it on our list?

The real problem is that it is often used as a cheap protein source in dog food. It is an incomplete protein and does even come close to the nutrition provided by protein from named and healthy animal sources. 

If you find brewers rice high up on your dog food's ingredient list, then it can indicate that your dog is not getting as much animal protein as the packaging may lead you to believe. 


Healthy Alternative: Choose Whole Grains

Look for whole-grain sources or whole vegetable and legume carbohydrate sources for more nutrition and longer-lasting energy for your dog.


20. Corn


Corn does get a bad reputation as a dog food ingredient. While corn itself is a whole grain, there are a number of things wrong with it as an ingredient in pet foods.

Corn is notoriously hard to digest. Many pets have digestive sensitivities related to corn. Also, since it has a high protein concentration for a grain, it is often added to dog food to raise the protein percentages.

However, this protein does not contain all the necessary amino acids and is not nearly as bioavailable as any animal source, such as chicken or eggs. Lastly, corn is a subsidized, very cheap grain, so its inclusion is a marker that your pet food is looking to cut corners on nutrition for profit.


Healthy Alternative: Look for Meat Proteins or Go Grain-Free

There are many better alternatives to corn. Look for nutrient-rich vegetables, such as sweet potato, to provide necessary carbohydrates and look for plenty of named meats such as chicken, pork, beef, or salmon for quality meat protein. 

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21. Sodium Hexametaphosphate

This common additive in dental care dog food diets may be helpful for reducing your pet's tartar, but at what cost? Sodium hexametaphosphate is dangerous in high doses but can also have adverse effects merely with ingestion.

For humans, the chemical is a skin irritant and an inhalation irritant, as well as being hazardous to ingest. While tartar prevention is useful, could this preventative be doing more harm than good as a non-nutritive additive to your pet's food?


Healthy Alternative: Brush Your Pet's Teeth

There is no substitute for regular dental care for your pet. Brush teeth, make use of dental care products such as tooth gels, sprays, or oral probiotics, and if necessary, schedule a veterinary cleaning.

With these measures, you shouldn't have to rely on dental food for your pet with questionable ingredients. For more dental care options, check out our recommendations for dental treats for dogs with bad breath


22. Flavour

Food needs flavour to be appealing. However, the flavour is one of those things that should just come naturally to foods. Be skeptical about the quality of ingredients when flavour needs to be added. 

According to the FDA, artificial flavours are rare and usually take the form of bacon or smoke flavour. Flavour can be listed by itself or with something else (e.g. Bacon flavour).

But just because a flavour is listed as “bacon flavour”, does not mean it is natural. Unless the ingredient is listed as natural, assume it is artificial. “Flavour” can also cover up those undesirable ingredients that manufacturers know you are looking out for, like MSG.

You don’t know what you’re getting. Potential allergens such as dairy, soy, sesame, eggs, and nuts are also possible inclusions. 


Healthy Alternative: Skip It

Why choose artificial when there are plenty of natural, delicious flavours out there? Choose food and treats that use a variety of fresh and healthy animal proteins, vegetables, fruits, and botanicals.


23. Pea Protein


Peas are a good source of fibre and carbohydrates and even contain a high amount of protein for a vegetable.

However, when this popular legume is listed only as "pea protein" you should look at it critically. These peas in your dog food ingredient list are dried peas, similar to split peas, not the fresh peas in a pod you might be thinking of.

Pea protein has risen to popularity as an ingredient in many cheaper grain-free pet foods. Containing 55% protein in its concentrated form, pea protein can be used to boost the protein content of food cheaply.

When pea protein is included in your pet's food, the manufacturer could be trying to make up for a lack of meat-based protein.

Pea protein is not complete in amino acids as animal proteins are, and it's biological value is not as high. That means that your dog will not be able to use all of the protein within peas. 


Healthy Alternative: Skip It

Avoid foods with pea protein high up in the ingredient list, especially within the first 7 ingredients. If it's lower than that, it's less likely to make a big difference in the protein makeup of your pet's food.


24. Animal Digest

Animal digest is another non-descript meat source produced by the chemical or enzymatic hydrolysis of clean animal tissue that has not undergone decomposition.

Basically, it is a mixed “meat” broth that is heavily processed. Used as a flavouring, it is sprayed onto dog food to cover up unsavoury flavours and make up for a lack of actual meat flavour from, you know, meat. According to the FDA:

“With respect to flavors, pet foods often contain "digests," which are materials treated with heat,enzymes and/or acids to form concentrated natural flavors. Only a small amount of a "chicken digest" is needed to produce a "Chicken Flavored Cat Food," even though no actual chicken is added to the food.”


Healthy Alternative: Choose Better Quality

The inclusion of animal digest or any digest indicates that insufficient meat protein is included in the food. After all, if the food contained plenty of healthy, nutritive, and protein-rich meat, why the need for meat flavour?



There are many high quality dog foods out there, like Orijen, Fromm, or Ziwi Peak. This super-premium, minimally processed foods are filled with nutritional ingredients such as free-range chicken, organic vegetables, and whole fruits complete with antioxidants.

These foods do not contain cheap, questionable ingredients that many manufacturers use to turn a high profit or make their food impossibly cheap.

Price is not always an indicator of quality, but the ingredients list doesn't lie – if you know how to read it. The first step is checking for these 24 ingredients bad for dogs.

There are so many good, healthful things you can include in your dog's diet. Please, do your dog a favour and skip these.

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What are some ingredients that you avoid feeding your dog? Bad Dog Food Ingredients? Let us know in the comments below!


Written by

Amy Dyck


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