Published July 19, 2026 · Reviewed by the Unbiased Advice & Insights editorial team · How we research and score
Choosing the right cat food can be overwhelming, especially when ingredient lists are full of unpronounceable names. Some common additives have been linked to health concerns in cats. Our editorial team compared specifications, buyer feedback and key decision factors to help you understand which ingredients to avoid and why.
Why Ingredients Matter
Cats are obligate carnivores, meaning their bodies are designed to thrive on a meat-based diet. Artificial preservatives, thickeners, and colors serve no nutritional purpose and may pose risks. Long-term exposure to certain chemicals has been associated with cancer, allergies, and digestive issues. Being an informed label reader is the first step to protecting your cat's health. For example, a study by the FDA found that BHA caused tumors in the forestomach of rats, raising concerns for cats. Similarly, ethoxyquin has been linked to liver and kidney damage in dogs, and similar effects are suspected in cats. By choosing foods without these additives, you reduce the cumulative chemical burden on your cat's body.
BHA and BHT
BHA (butylated hydroxyanisole) and BHT (butylated hydroxytoluene) are synthetic antioxidants used to prevent fats from going rancid. They are common in many dry cat foods and treats. Studies have linked BHA to cancer in laboratory animals, and BHT may cause liver and kidney damage. While regulatory agencies still consider them safe in small amounts, many pet nutritionists recommend avoiding them. Check the ingredient list for these names or the phrases "preserved with BHA/BHT." For instance, some popular budget-friendly brands still use BHA to extend shelf life. If you see it, consider switching to a brand that uses natural preservatives like mixed tocopherols.
Ethoxyquin
Ethoxyquin is a chemical preservative originally developed for rubber and used in some pet foods to stabilize fats. It is controversial because of potential links to liver damage, immune system issues, and cancer. Although the FDA approved it, many pet food manufacturers have voluntarily phased it out. Look for ethoxyquin in the ingredient list; it may also appear as "ethoxyquin (a preservative)." If you see it, choose another brand. Some fish-based foods are more likely to contain ethoxyquin because fish oils are prone to oxidation. Always check labels on salmon or tuna formulas.
Carrageenan
Carrageenan is a thickener derived from red seaweed, often used in wet cat foods to create a gravy-like texture. While food-grade carrageenan is considered safe, some studies indicate that degraded carrageenan (a contaminant) can cause gastrointestinal inflammation and may be carcinogenic. Many cats with sensitive stomachs do better without it. Look for carrageenan in the ingredient list; alternatives include guar gum or xanthan gum. For example, a cat with chronic diarrhea may improve when switched to a carrageenan-free food. Brands like Tiki Cat and Weruva often avoid carrageenan.
Artificial Colors
Artificial colors like Red 40, Yellow 5, Yellow 6, and Blue 2 are added to make cat food look more appealing to humans, but cats don't care about color. These dyes have been linked to hyperactivity, allergies, and potential carcinogenic effects in some studies. They offer no nutritional benefit. Avoid any cat food that lists artificial colors; opt for brands that use natural colorings or none at all. For instance, some grocery store brands use Red 40 to make chunks look like meat. Instead, choose foods that rely on natural ingredients like beet powder or turmeric for color, if any.
How to Spot Them on Labels
- Read the full ingredient list. Ingredients are listed by weight, so harmful additives may appear near the end.
- Look for specific names: BHA, BHT, ethoxyquin, carrageenan, and any FD&C colors (e.g., FD&C Red No. 40).
- Watch for vague terms like "preservatives" or "artificial flavors" which can hide these substances.
- Check the brand's website or contact customer service if you are unsure about an ingredient.
- Choose foods with clear, simple ingredient lists and named protein sources (e.g., "chicken" instead of "poultry meal").
- Be aware of "natural flavor" which may include chemical enhancers. Opt for brands that specify the source, like "chicken liver flavor."
Safer Alternatives
Instead of BHA/BHT, look for foods preserved with natural antioxidants like mixed tocopherols (vitamin E), ascorbic acid (vitamin C), or rosemary extract. For thickeners, opt for guar gum, xanthan gum, or agar-agar instead of carrageenan. Avoid artificial colors entirely; most high-quality brands do not use them. Choose foods that list whole meats and named meat meals as primary ingredients, and avoid by-products and unnamed animal meals. Brands like Wellness, Blue Buffalo, and Merrick often avoid these harmful additives, but always check labels as formulations change. For example, Wellness CORE grain-free recipes use mixed tocopherols and avoid carrageenan. Similarly, Merrick's Classic line uses guar gum and no artificial colors.
Frequently Asked Questions
Are all artificial preservatives bad for cats?
Not all. Natural preservatives like vitamin E (mixed tocopherols) and vitamin C (ascorbic acid) are safe. The harmful ones are synthetic antioxidants such as BHA, BHT, and ethoxyquin, which have been linked to health issues.
Can carrageenan cause cancer in cats?
There is concern that degraded carrageenan (a byproduct) may be carcinogenic. While food-grade carrageenan is generally recognized as safe in small amounts, some studies suggest it can cause gastrointestinal inflammation. Many pet food makers now avoid it.
What should I look for on a cat food label to avoid harmful ingredients?
Check the ingredient list for BHA, BHT, ethoxyquin, carrageenan, and artificial colors like Red 40, Yellow 5, Blue 2. Also look for vague terms like "animal digest" or "meat by-products" which may contain low-quality ingredients.
Is propylene glycol safe in cat food?
Propylene glycol is sometimes used as a humectant in semi-moist cat foods. However, it can cause Heinz body anemia in cats, a condition that damages red blood cells. It is banned in cat food in some countries. Avoid any product listing propylene glycol.
What about rendered fats like "animal fat"?
Rendered fats from unspecified sources may contain preservatives like BHA/BHT. They can also come from diseased or dead animals. Look for named fats such as "chicken fat" preserved with natural antioxidants.
More guides
See our full buying guides hub and our research and scoring methodology. We compared specifications and verified owner feedback; we did not physically test every product.