Ingredient database › Blue 2
Is Blue 2 good or bad in dog food?
Blue 2 is a colouring agent and rates as Avoid in our analysis.
Avoid Bottom line: Blue 2 is best avoided — it has no real place in dog food and pulls a recipe's grade down.
Artificial dye — cosmetic only.
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 Blue 2?
Blue 2 is a colouring agent used in dog food. On a label it may also appear as: blue 2, fd&c blue no. 2, indigotine.
What to look for on the label
Ingredients are listed by weight, so the ones near the top make up most of the recipe. Blue 2 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 Blue 2 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. Blue 2 contributes as a avoid-tier item; read the full scoring methodology to see exactly how the grade is calculated.