Ingredient database › Onion
Is Onion good or bad in dog food?
Onion is an additive and rates as Avoid in our analysis.
Avoid Bottom line: Onion is best avoided — it has no real place in dog food and pulls a recipe's grade down.
Toxic to dogs — should not be in dog food.
This is an ingredient we'd avoid. When it shows up — particularly near the start of the list — it pulls the whole recipe's grade down.
Built on AAFCO & FDA pet-food criteria · Last updated June 2026 · How we rate
What is Onion?
Onion is an additive used in dog food. On a label it may also appear as: onion, onion powder.
What to look for on the label
Ingredients are listed by weight, so the ones near the top make up most of the recipe. Onion ideally should not be in your dog's food at all. The fastest way to judge a whole product is to paste its full ingredient list into our free dog food checker, which grades it A–F and flags every ingredient like this one.
How Onion affects the WoofScore
Our grade rewards named whole proteins, vegetables, fruit and beneficial supplements, and penalises vague by-products, cheap fillers, artificial colours and controversial preservatives. Onion contributes as a avoid-tier item; read the full scoring methodology to see exactly how the grade is calculated.