Understanding the ingredient list

Chicken meal, lamb meal, salmon meal

Meat that has been cooked, separated from fat and water, and dried to a meal of roughly 65% protein. Because it is already dry, its position in the list reflects fairly closely how much is in the finished bag. The word in front — chicken, lamb — names the species, which is what you need if your animal must avoid a particular protein.

Chicken, fresh chicken, deboned chicken

Fresh meat, of which about 70% is water. Ingredient lists are ordered by weight before cooking, so a fresh item at the top of the list can fall a long way down once the moisture is driven off. First on the list does not mean most in the bag.

Dehydrated poultry protein, poultry meal

Also a dried meat meal, but "poultry" is a category rather than a species — it may be chicken, turkey, duck or a mix, and may change between batches. Neither wrong nor inferior, but if you are eliminating one specific protein this wording is not something you can rely on.

Meat and animal derivatives

A legally permitted category name covering parts of the animal other than plain muscle meat: liver, heart, lung, kidney. In fairness, organ meat is nutritionally rich — liver and heart typically beat muscle meat on vitamins and minerals. But the same term also permits lower-value material, and the label does not tell you which end of that range your bag sits at.

Hydrolysed animal protein

Protein broken down into short fragments. It has two quite different uses. One is as a palatant coating that makes the kibble worth eating. The other is in diets for allergic animals: the fragments are small enough that the immune system no longer recognises them, so no reaction is triggered. This is good technology, not a warning sign.

Maize gluten, wheat gluten, vegetable protein isolate

Concentrated plant protein with a very high protein content. It raises the crude protein figure on the label, but its amino acid profile differs from animal protein — it is limiting in several essential amino acids and supplies no taurine, which cats must obtain from food. Nothing harmful about it; the point is that the crude protein number alone cannot tell these sources apart.

Maize, corn, rice, wheat, barley

Energy sources. Well cooked, dogs digest cereals very efficiently; cats tolerate starch less well but handle moderate levels without trouble. Grain gets called filler more often than it deserves — it delivers real energy, and a grain-free formula still has to get its starch from somewhere, usually potato or pulses.

Cereals

The category name, meaning "some cereal". It lets the maker move between wheat, maize and barley according to price and supply from batch to batch without reprinting the packaging.

Beet pulp, sugar beet pulp

What is left of the sugar beet after the sugar is taken out. It is a moderately fermentable fibre that feeds beneficial bacteria in the large intestine and helps firm the stool. It has a reputation as filler, but it is in fact one of the best-studied and genuinely useful fibres.

FOS, MOS, chicory inulin

Soluble fibres that feed the gut’s beneficial bacteria — prebiotics. They are present in very small amounts, so they always sit at the end of the list.

Psyllium husks and seeds

Psyllium, a fibre that absorbs a great deal of water. Common in formulas aimed at animals with loose stools or easily upset digestion.

Cellulose, powdered cellulose

A non-fermentable fibre that essentially adds bulk. Used in weight-control formulas so the animal feels full without extra calories, and in hairball formulas for cats.

Chicken fat, salmon oil, fish oil

Fats with their source named. These are the densest energy source in the food and carry the fat-soluble vitamins with them. Fish oils additionally supply EPA and DHA, the long-chain omega-3s associated with skin, coat and joints.

Animal fats, oils and fats

The category name, with no species stated. Nutritionally, fat is still fat; what you cannot tell is which animal it came from — which matters if you are eliminating a protein.

Sunflower oil, soya oil, borage oil

Plant oils, mainly supplying the omega-6 fats for skin and coat. Borage oil is added for its GLA content and turns up in formulas aimed at sensitive skin.

Yeasts and parts thereof, brewers yeast

A source of B vitamins and the raw material for the MOS prebiotics. Used in small amounts.

Hydrolysed crustaceans, hydrolysed cartilage

The label wording for glucosamine and chondroitin, the two compounds usually added to joint-support formulas. Being at the end of the list, the amounts are small; the label does not tell you enough to compare them with a joint supplement dose.

Taurine

An amino acid that must be present in cat food — cats cannot make enough of it themselves, and a deficiency leads to heart muscle disease and retinal degeneration. Every complete cat food has to contain it.

Marigold extract, lutein

Marigold extract, a source of the antioxidant lutein.

Minerals, trace elements, zinc proteinate, zinc amino acid complex

The added mineral portion. The words proteinate or amino acid complex mean the mineral is bound to an amino acid — a form the body absorbs better than a plain mineral salt.

Mixed tocopherols, tocopherol-rich extracts, ascorbic acid

Natural antioxidants — tocopherols are vitamin E, ascorbic acid is vitamin C. They keep the fat in the food from going rancid. They typically give a shorter shelf life than synthetic preservatives.

BHA, BHT, ethoxyquin

Synthetic antioxidants, which keep longer. They remain permitted within regulated limits, though many makers have moved to natural alternatives because buyers prefer them. Note that a preservative added earlier by an ingredient supplier need not always appear on the finished label.

EC permitted additives, antioxidants

A collective wording that names no specific substance. Knowing exactly which one was used means asking the manufacturer.