Ingredient Concerns

We flag 42 ingredients across the pet foods we analyze. Here's what to watch for and why.

Every ingredient in your pet's food tells a story. Some are nutritional powerhouses, while others are worth a closer look. We review thousands of pet food labels and flag the ingredients that veterinary research suggests you should know about. Each entry below explains why it caught our attention and how many products contain it.

BHA 57 products

BHA (butylated hydroxyanisole) is a synthetic preservative classified as 'reasonably anticipated to be a human carcinoge...

Sodium Nitrite 45 products

A preservative that has caused fatal reactions in cats eating commercial pet food. Cats are uniquely sensitive because t...

Cats only
Ethoxyquin 9 products

Ethoxyquin is a synthetic antioxidant originally developed as a pesticide. Banned in pet food in the EU and Australia. T...

Propylene Glycol 0 products

Propylene glycol is banned in cat food by the FDA. It damages red blood cells in cats, and unlike dogs or humans, cats c...

Cats only
STPP (Phosphate) 320 products

An inorganic phosphate additive. The phosphorus in additives like this hits a cat's system much harder than the natural...

Cats only
Caramel Color 160 products

A cosmetic dye. Your pet doesn't care what color their food is. Some types of caramel color contain a byproduct (4-MEI)...

Phosphoric Acid 133 products

An inorganic phosphate source. A cat's body absorbs this kind of phosphorus much more aggressively than the natural phos...

Cats only
Garlic 87 products

A member of the allium family. Contains thiosulfate compounds that cause oxidative damage to red blood cells. Some dog f...

Red 40 68 products

Red 40 (Allura Red AC) is an artificial dye with zero nutritional purpose, added solely to make food visually appealing...

Yellow 5 67 products

Yellow 5 (Tartrazine) is an artificial dye. Requires warning labels in the EU. No nutritional function.

Blue 2 58 products

Blue 2 (Indigo Carmine) is an artificial dye. No nutritional function.

Titanium Dioxide 56 products

Titanium dioxide is a whitening agent banned as a food additive in the EU since 2022 due to genotoxicity concerns (EFSA...

Sodium Nitrite 56 products

A preservative that can form cancer-linked nitrosamine compounds when combined with proteins during processing. Dogs are...

Dogs only
Yellow 6 48 products

Yellow 6 (Sunset Yellow) is an artificial dye. Banned or requires warning labels in several EU countries. No nutritional...

Corn Syrup 17 products

An added sugar with no nutritional value. Used as a flavor enhancer and binder. Contributes to obesity, dental decay, an...

BHT 8 products

BHT (butylated hydroxytoluene) is a synthetic preservative. Animal studies show potential liver and kidney effects at hi...

TBHQ 5 products

TBHQ (tertiary butylhydroquinone) is a synthetic fat preservative. Dogs are the most sensitive species to TBHQ according...

Dogs only
Onion 4 products

A member of the allium family. Contains thiosulfate compounds that cause oxidative damage to red blood cells (Heinz body...

High Fructose Corn Syrup 3 products

An added sugar with no nutritional value. Contributes to obesity, dental decay, and insulin resistance over time.

Sucrose (Sugar) 3 products

Table sugar added as a flavor enhancer. No nutritional value and contributes to obesity, dental decay, and blood sugar i...

TBHQ 2 products

TBHQ (tertiary butylhydroquinone) is a synthetic fat preservative. Dogs are the most sensitive species to TBHQ according...

Cats only
Meat & Bone Meal 0 products

A generic rendered ingredient where the animal source isn't identified. It could be any mammal. FDA testing has found co...

Soy Protein 0 products

Soy contains compounds called isoflavones that can nudge thyroid hormone levels in cats. What makes this tricky is that...

Cats only
Menadione 1554 products

Menadione sodium bisulfite (synthetic vitamin K3) is banned in human food supplements in some countries. Natural vitamin...

Omega-3 Source Quality 1042 products

Fish oil, salmon oil, and algal oil deliver EPA and DHA directly, the omega-3 forms pets actually use. Plant sources lik...

Carrageenan 646 products

Carrageenan is a seaweed-derived thickener. Food-grade carrageenan is GRAS, but degraded carrageenan (poligeenan) is an...

Ingredient Splitting 629 products

Some foods list multiple forms of the same ingredient (like pea protein, pea fiber, and pea starch instead of just peas)...

Whole Meat Label Position 463 products

In dry food, fresh meat like "chicken" is about 70% water. Ingredients are listed by pre-cooking weight, so meat appears...

Cellulose (Filler) 341 products

Purified plant fiber, essentially wood pulp. Not digestible, but that's the point in weight management formulas: it adds...

Cats only
STPP (Phosphate) 288 products

An inorganic phosphate additive, commonly used in dental treats for tartar control. Dogs handle inorganic phosphorus bet...

Dogs only
Artificial Flavors 184 products

Artificial flavors suggest the base ingredients may lack palatability on their own. Not a health risk per se, but a qual...

Cellulose (Filler) 180 products

Purified plant fiber, essentially wood pulp. Not digestible, but that's the point in weight management formulas: it adds...

Dogs only
Corn Protein 155 products

A plant-based protein used to bump up the protein number on the label at a lower cost. Cats are obligate carnivores, so...

Cats only
Corn Protein 149 products

A plant-based protein used to bump up the protein number on the label at a lower cost. Dogs can use plant proteins bette...

Dogs only
Iron Oxide (Color) 109 products

A colorant added to make food look meaty for your benefit, not your pet's. Not harmful, but not doing anything useful ei...

Animal Fat (Generic) 92 products

A generic rendered fat where the animal source isn't identified. Named fats like 'chicken fat' or 'beef fat' tell you ex...

Corn Gluten 88 products

A plant-based protein used to bump up the protein number on the label at a lower cost. Dogs can use plant proteins bette...

Dogs only
Corn Gluten 75 products

A plant-based protein used to bump up the protein number on the label at a lower cost. Cats are obligate carnivores, so...

Cats only
Animal Digest 17 products

A palatability enhancer made by hydrolyzing unspecified animal tissues into a liquid or powder. The animal source is not...

Phosphoric Acid 16 products

An inorganic phosphate source. Dogs handle inorganic phosphorus better than cats, but it is still absorbed more aggressi...

Dogs only
Propylene Glycol 7 products

A synthetic humectant used in semi-moist dog foods to retain moisture and texture. Banned in cat food (damages cat red b...

Dogs only
Soy Protein 0 products

Soy is one of the more common food allergens in dogs and contains phytoestrogens (isoflavones) that may affect hormone l...

Dogs only