How to read a pet food label when you are avoiding an ingredient

Chicken appears on labels as chicken meal, chicken fat, chicken liver, chicken by-products, chicken digest, chicken broth — and, less obviously, as poultry, poultry meal, poultry fat and poultry by-products, any of which may or may not include chicken. Beef hides behind beef meal, beef tallow, beef digest and bovine. Dairy arrives as whey, casein, lactose and milk protein.

This is why "chicken-free" as a shopping instruction fails in practice. A label can avoid the word chicken entirely and still contain it. Our allergen pages list the known alternative names for each common trigger so you can scan for the whole family rather than one word.

One nuance on fats: highly refined fats contain very little protein, and protein is what the immune system reacts to. Many animals tolerate them. That is a conversation for your vet rather than a rule — but it explains why some vets are relaxed about chicken fat in a chicken-allergic dog.

Ingredients are listed by weight, heaviest first. Manufacturers can therefore move an ingredient down the list by splitting it into components — listing ground corn, corn gluten meal and corn bran separately instead of corn as a single line. Each fragment weighs less than the combined total, so each appears further down, and a food built substantially on one grain can look like it is built on meat.

When scanning a label, mentally recombine anything sharing a root word. If three corn-derived items appear in the first six ingredients, corn is a major component regardless of where each individual entry sits.

There is no regulated definition of "hypoallergenic," "limited ingredient," or "natural" in pet food. A manufacturer may apply them freely, and testing of over-the-counter diets has repeatedly found proteins not declared on the label — including in foods marketed specifically for allergic animals.

For everyday feeding of an animal with a known trigger, a carefully read label is usually adequate. For a diagnostic elimination trial it is not, and that is the case for a veterinary hydrolysed or novel-protein diet during the trial period specifically.