12 Dog Food Ingredients Bad for Your Pet’s Health and Longevity

Making sure your dog is well-fed is pet care 101. Most pet parents spend a lot of effort and energy—be it in the form of looking for the right food for their canine companion or making home cooked meals from scratch—in getting it right. However, in their quest to find the right food for their pets, a vast majority of them overlook a critical aspect of canine nutrition—dog food ingredients to avoid because they’re harmful for your pet’s health and longevity. 

This is especially true for those who are just beginning their journey into pet parenting. Been there. After all, with so many options on the shelf, with such a wide range of brands, ingredients, and specialities, not to mention prices, picking out dog food that hits that sweet spot of long-term affordability and meeting your dog’s nutritional needs can get tricky as well as overwhelming. 

In my early days as a pet parent, I, too, started out with commercially packaged dog food for my furry baby. That led to digestive issues, allergic reactions, deficiencies triggered by one brand or the other. As a result, I lean in favor of nutritionally complete home-cooked meals for my dogs, however, the practicality and convenience of packaged dog food cannot be ruled out. On occasion, I still use it, and with years of practice, I’ve gotten better at picking them too.  

The key, you see, is to pay attention to the food labels and take your time going over them with a fine-tooth comb. And you will find everything you need to know about the quality of a particular dog food, or lack thereof—right from harmful ingredients in dog food to unhealthy dog food fillers, toxic dog food additives. In this guide, I will take you through the common harmful ingredients in dog food as well as healthier alternatives you should look out for when reading the labels. 

The Importance of Reading Dog Food Labels

Since I’ve been emphasizing reading labels, let’s start by talking in detail about why it’s so important. Veterinarian Dr. Jess explains that a proper understanding of the ingredient list helps identify high-quality food sources as well as fillers and additives to avoid in dog food. “Ingredients are listed by weight, so top-listed proteins often indicate a quality food,” she explains. 

However, to identify unhealthy dog food fillers, you need an eye for detail. If a particular food has beef or chicken listed among the top three ingredients, then it is high-quality food that supports your pet’s nutritional needs and contributes to muscle maintenance. On the other hand, terms like “beef flavor” or “with chicken” indicate that the food may contain as little as 3% of the named ingredient, and as a result, offer little nutritional value to your dog. 

When checking for nutritionally empty or common harmful ingredients in dog food, it helps to pay attention to the “guaranteed analysis” on the label that provides insight into the food’s nutritional composition, including macro nutrients like protein, fat, and fiber content. It’s also important to watch for additives such as artificial colors as well toxic preservatives in dog food that can be harmful in the long-term. 

Canine nutritionists recommend that quality dog food must contain an adequate amount of protein and fat to meet dogs’ nutritional needs as well as strengthen their immune functions. Added omega fatty acids and probiotics are the cherry on top. 

Dr. Julia Ogden from Dog Food Advisor recommends prioritizing “natural” or “organic” foods to avoid synthetic chemicals. However, these terms can be loosely regulated. By reading the labels closely, you can zero-in on nutrient-rich foods made from well-sourced ingredients. If you’re struggling to make sense of dog food labels or are unable to differentiate between healthy ingredients and unhealthy dog food fillers, it’s always wise to consult a veterinarian for guidance.

Suggested Reading: How Long Does It Take a Dog to Digest Food?

12 Harmful Dog Food Ingredients to Avoid

Now that we’ve firmly established that the key to picking out the right food for your dog lies in reading the labels attentively, let’s turn our attention to which ingredients serve as red flags of nutritionally compromised food for your pet. Here is a compilation of 12 harmful dog food ingredients to avoid:

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

These chemical preservatives used to extend shelf life are known to cause cancer in dogs. Veterinarian Dr. Carol Osborne notes, “BHA and BHT are banned in some countries due to carcinogenic concerns, and dog owners should consider alternatives.” These are two of the most toxic preservatives in dog food and must be avoided at all costs. If you cannot find packaged dog food free of these preservatives, I’d recommend switching to nutritionally complete homemade meals, any day.  

2. Ethoxyquin

Speaking of toxic dog food additives, ethoxyquin is another one you want to steer clear of. Long-term exposure to this preservative is linked to serious health issues such as liver and kidney damage. Given that it was initially developed as a pesticide, it’s hardly surprising. 

3. Artificial colors (e.g., Blue 2, Red 40, Yellow 5 and 6)

Artificial dyes among the ingredients in dog food linked to health problems, as they can trigger allergic reactions and hyperactivity. Given that they are added solely for visual appeal and add no nutritional value to your dog, there is no reason why you should be putting any food containing dyes in your dog’s bowl. 

4. Corn syrup

Corn syrup is a high-glycemic sweetener that adds sugar content to dog food and can be a strong contributing factor to obesity and diabetes. This is one of the most dangerous dog food ingredients given that sugar is harmful for dogs and can put dogs prone to diabetes at a higher risk. 

5. MSG (Monosodium Glutamate)

When talking about fillers and additives to avoid in dog food, MSG just cannot be overlooked. Like other flavor-enhancers and additives, it serves no nutritional purpose but can cause serious neurological issues in dogs, including seizures. Besides, MSG can unnecessarily stimulate dogs’ appetites, leading to overeating and weight gain.
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6. Rendered fat

While dogs need a certain amount of good fat in their diet, “good” is the operative word here and rendered fat does not meet that criteria by a long shot. It is a low-quality fat source prone to contamination by bacteria or toxins. It may also introduce carcinogenic substances into the food​, making it one of the most harmful ingredients in dog food.  

7. Propylene Glycol

Used for maintaining moisture, propylene glycol, also found in antifreeze (which should tell you all about why it’s among the dog food ingredients to avoid), can cause digestive issues in dogs. Veterinarian Dr. Karen Becker warns, “This ingredient can reduce healthy gut bacteria, weakening dogs’ immune systems.”​

8. Meat by-products

Some meat by-products like organs and offals are nutritious for dogs, unidentified “meat by-products” raise a red flag about the quality of the food as these can comprise unregulated animal parts, including meat sourced from road kills. It’s always advisable to choose a food that lists a specific protein source like chicken or feed, instead of meat by-products.

9. Corn and wheat gluten

Veterinarian Dr. Richard Pitcairn notes, “Dogs have a limited ability to digest grains, which can lead to digestive upset and inflammation.”​ That’s why inexpensive and unhealthy dog food fillers that lack nutritional value and have the potential to trigger allergies are best avoided.

10. Soy

Veterinarian Dr. Jean Dodds warns that soy can disrupt thyroid function in dogs. This cheap protein alternative can also interfere with hormone levels and is a common allergen for dogs. If you’re wondering how to identify low-quality ingredients in dog food, know that any food that lists soy among its primary ingredients fits the bill and you best steer clear of it. 

11. Sodium Nitrate and Nitrite

Also commonly used as preservatives, these chemicals are associated with cancer and heart disease in dogs, and you wouldn’t want to serve any food laced with them to your beloved pet. Dr. Becker warns, “Sodium nitrates should be avoided, as they convert to nitrosamines in the stomach, which are carcinogenic.”​

12. Carrageenan

Commonly used as a preservative in canned foods, carrageenan has been linked to gastrointestinal inflammation and cancer in our canine companions. This is another potentially harmful additive in dog food and must be avoided. 

Watch the video to know more:

What to Look for Instead: Healthier Dog Food Ingredients

Now that you know there can be many harmful ingredients in dog food, you must realize how critical it is to be astute about what you feed your pet. A common advice you may come across is to choose packaged foods made from high-quality ingredients. But what are these high-quality ingredients? Let’s find out:

1. High-quality animal protein

Protein is crucial for your pet’s overall health and well-being, and affects everything from muscle maintenance and overall energy. That’s why Dr. Becker recommends that “real meat should be the primary ingredient, as it provides essential amino acids for muscle and organ health.” So pick the dog food that lists chicken, beef, turkey, or pork as its first ingredient. ​

Suggested Reading: Can Dogs Eat Raw Chicken? Risks, Benefits, And Things to Consider

2. Whole grains

Whole grains such as brown rice, oats, and barley are great sources of fiber as well as micro-nutrients like vitamins and minerals. Besides, they provide more balanced energy and support digestion. They are definitely a whole lot better for your dog’s nutritional needs than unhealthy dog food fillers like corn. So, if you’re on the lookout for packaged dog food with healthy ingredients, choose one that comprises whole grains.

3. Omega-3 and Omega-6 Fatty Acids

These essential fats support skin health, coat shine, and joint health as well as play a key role in reducing inflammation and promoting heart health. Any dog food that is fortified with these key nutrients through ingredients like fish oil or flaxseed is a good pick for your pet.

4. Pumpkin

Pumpkin is great for dogs’ digestive health. It helps soothe their tummies, prevents digestive distress, and promotes healthy weight. It is also a great natural source of fiber. Pumpkin is, by all measures, a great addition to your dog’s diet, and you should look for food options that incorporate it as a key ingredient or even consider topping up your dog’s meals with a spoonful of canned pumpkin. 

5. Sweet potatoes

Sweet potatoes are an excellent complex carbohydrate—easily digestible, packed with fiber, vitamins A and C, and antioxidants, and a great source of energy. Definitely an ingredient you should incorporate in your dog’s diet.

6. Carrots

Low in calories and high in fiber and beta-carotene, carrots are great for canine eye health and immunity. Dog foods made from high-quality ingredients like carrots are undoubtedly safe and healthy for your dog (of course, when I say that, I mean as long as they’re free from toxic dog food additives, preservatives, fillers, and other low-quality ingredients). 

Suggested Reading: Can Dogs Eat Almonds?

Apart from looking for dog foods that have carrots as an ingredient, you can also consider offering it to your pet as a snack. It helps them clean their teeth and is great for maintaining your pet’s dental health. 

7. Calcium and phosphorus

Calcium and phosphorus are essential for your pet’s bone health. If you can find dog food that incorporates these key nutrients in adequate quantities, through ingredients like bones or fish, it can be immensely beneficial for supporting their skeletal growth and strength. If the food you’re giving your dog isn’t fortified with these nutrients, consider talking to your vet about supplements, especially if you have a growing puppy. 

Suggested Reading: Can You Mix Wet and Dry Dog Food?

FAQs 

1. Why is meat meal bad for dogs?

Meat meal, while high in protein, can be problematic in dog food due to varying quality and lack of transparency. General terms like “meat meal” or “animal meal” may include unidentified or low-quality meats, such as by-products and connective tissue, which are less digestible and offer limited nutritional value. Meat meals can also contain 4-D meats (from dead, diseased, dying, or disabled animals), raising the risk of contaminants or toxins. These meals are typically highly processed at high temperatures, which can destroy beneficial nutrients and introduce harmful residues​.

2. What preservatives should I avoid in dog food?

Certain preservatives in dog food can be harmful, linked to potential long-term health issues like cancer, organ damage, and allergies. These include: 

• BHA (Butylated Hydroxyanisole): Suspected carcinogen that can cause liver and kidney damage​
• BHT (Butylated Hydroxytoluene): Linked to cancer and liver issues in animals​
• Ethoxyquin: Often used as a pesticide; associated with liver and kidney toxicity​
• Propylene Glycol: Can reduce healthy gut bacteria, weakening immune systems​
• Sodium Nitrite and Nitrate: Carcinogenic compounds that may harm heart and overall health​

3. Is grain-free food always better?

Grain-free dog food isn’t always better and may not suit every dog. While it can help dogs with specific grain allergies or sensitivities, grain-free diets replace grains with ingredients like potatoes or legumes, which don’t always provide balanced nutrition. The FDA has even investigated potential links between grain-free diets and canine dilated cardiomyopathy (DCM), a heart condition, though research is ongoing. Veterinarians often recommend grain-inclusive diets unless a specific allergy is diagnosed, as whole grains like brown rice and oats can support digestion and provide essential nutrients​.

Takeaway 

The food you choose for your dog can have far-reading effects on every aspect of their health, right from energy levels to immunity, gut health, skin health, as well as risk of allergies, infections, and other serious diseases like cancer. It’s critical that you choose wisely because not all dog food is created equal. If you don’t invest in quality food and nutrition, you will have to spend on medicines and vet bills—except, the latter comes with significant stress and trauma for both you and your dog. So, choose wisely.