Game of Bones field guide

What Are Fillers?

Corn, wheat, soy, cellulose — 'fillers' show up constantly in pet food conversations. Here's exactly what they are and why they matter.

Ingredients · 5 min read · Updated 16 July 2026 · Game of Bones team

What "Filler" Actually Means

A filler is any ingredient added to a pet food or treat primarily to add bulk, weight, or texture — not for meaningful nutritional value. Fillers aren't automatically "toxic" or dangerous; the concern is that they take up space in the ingredient list and in your dog's stomach that could otherwise go to real, usable nutrition.

Common Fillers on Indian Pet Food Labels

Filler	What It Does	Nutritional Value
Corn starch / corn meal	Cheap bulk and binding agent	Low — mostly empty carbohydrate
Wheat flour / wheat bran	Binding, texture	Low-moderate — some fibre
Soy flour	Cheap protein-percentage booster	Plant protein, incomplete amino acid profile for dogs
Cellulose (plant fibre)	Bulk, sometimes marketed as "fibre"	Essentially indigestible bulking agent
Glucose / corn syrup	Sweetener, palatability booster	None — pure added sugar

Why Manufacturers Use Fillers

Fillers are cheap. Real meat is the most expensive ingredient in any pet food formulation. Padding a product with grain starch or plant protein allows a manufacturer to list a higher "protein percentage" on the label using cheaper ingredients, while keeping costs — and price to the consumer — lower.

How to Spot Fillers on an Ingredient List

Ingredients are legally required to be listed in descending order by weight. If you see corn, wheat, soy, or "meal" of any kind within the first three ingredients — before a named animal protein — that product is built around filler, not meat.

🚫 Filler-Heavy Example

Corn meal, chicken meal, wheat flour, animal fat, soy flour, glucose syrup, sodium tripolyphosphate…

✓ Filler-Free Example

Chicken breast.

Are All Carbohydrates "Fillers"?

No — this is an important distinction. Sweet potato, pumpkin, oats, and brown rice, when used thoughtfully and in reasonable proportion, provide genuine fibre and micronutrients. The difference between a "filler" and a legitimate carbohydrate ingredient is proportion and purpose: a small amount of pumpkin for digestive fibre is not the same as corn starch making up 40% of a product purely to cut costs.

Why This Matters More for Treats Than Meals

A complete dog food needs some carbohydrate and fibre content to be nutritionally balanced. A treat, however, has no such requirement — it's a bonus, not a meal. There is no nutritional justification for filler in a treat at all, which is exactly why single-ingredient treats exist as a category: nothing to dilute, nothing to pad, nothing hidden.

The filler test: if you removed every ingredient except the named meat or fish, would there be anything nutritionally meaningful left? If the answer is "not much," you've found a filler-heavy product.

Shop single-ingredient treats →