How to choose dog food: what the label tells you and what it does not

Standing in front of the dog food shelf, the choice looks impossible. Bags promise »premium«, »holistic«, »packed with fresh meat« and »natural« – words that nobody regulates. The only part of the packaging that is governed by law, and that a manufacturer cannot simply invent, is the label on the back: a few lines of small print.

This guide explains what that small print actually says, which four figures are compulsory in the European Union, why dry and wet food cannot be compared side by side, and which questions are worth putting to a manufacturer. The labelling rules come from Regulation (EC) No 767/2009, which applies across the EU, and the nutritional statements from veterinary sources (WSAVA, the MSD Veterinary Manual, Tufts University). None of it replaces a conversation with your vet, especially for a dog with a diagnosed illness or a prescription diet.

First look: complete or complementary feed

The most important words on the bag are not the product name but the description of the feed type. Regulation (EC) No 767/2009 defines a complete feed as a compound feed which, by reason of its composition, is sufficient for a daily ration, and a complementary feed as one that is sufficient for a daily ration only if used together with other feed.

In practice: if the bag says »complete food for adult dogs«, your dog can live on it. If it says »complementary food«, it cannot – no matter how expensive the product is or how meaty it looks. Many meat-only cans, treats, toppers and food sprinkles fall into this category.

Next, look for the life stage: puppy, adult or senior. Recommended nutrient levels differ between life stages, and foods labelled »for all life stages« are formulated for growth and reproduction, which can be more than a calm older dog needs.

Composition: why it says »meat and animal derivatives«

Manufacturers may declare ingredients in two ways: by category (meat and animal derivatives, cereals, vegetables, minerals) or individually (dehydrated chicken protein, rice, corn gluten). Both are lawful. The Regulation requires ingredients to appear under the heading »composition« in descending order by weight, calculated on the basis of the moisture content of the compound feed.

The category »meat and animal derivatives« sounds worse than it is. The FEDIAF code defines it as all the fleshy parts of slaughtered warm-blooded land animals plus the products and derivatives of processing the carcass. That includes liver, heart, kidneys and tripe – parts that are nutritious but out of fashion in our own kitchens. Categories let a manufacturer adapt the recipe to whatever raw materials are available, and deprive the buyer of the precise information about which animal is in the bag.

Two rules are worth knowing whenever a single ingredient is highlighted on the front of the pack:

Those percentages may be calculated on a rehydrated basis, that is from the dried raw material – so »with chicken 4%« is not the same as 4% of fresh chicken in the bowl.

Analytical constituents: the four compulsory figures

Under the heading »analytical constituents«, four figures are compulsory for dog food in the EU: crude protein, crude fat, crude fibre and crude ash. Moisture has to be declared when it exceeds 14%, which in practice means on every wet food. The label may say »protein« instead of »crude protein«, and »incinerated residue« or »inorganic matter« instead of »crude ash«.

The word »ash« unsettles many owners, but it is laboratory language: nothing is added, it is the residue left after a sample is burned and it mostly represents minerals. A high ash figure is not in itself a sign of poor food – it mainly means more minerals, usually from bone-derived material.

The more important limitation is a different one. As the veterinary nutrition service at Tufts University explains, these numbers are a frame rather than an exact value: a food declaring 24% protein may well contain 26% or 32%. If you want the precise figure, ask the manufacturer for the »typical« or »average« analysis, ideally expressed per 100 or 1000 kcal.

Animals require nutrients, not ingredients. Two foods with nearly identical ingredient lists can differ considerably in quality. MSD Veterinary Manual

How to compare dry and wet food properly

This is the most common mistake in reading labels. Dry food contains roughly 10% water, wet food around 75–80%. The percentages on the pack refer to the product as it is – water included. Comparing them as printed therefore always leads to the wrong conclusion.

The fix is to convert to a dry matter basis: divide the nutrient level by (100 minus the moisture percentage) and multiply by 100.

The food that looks three times poorer in protein on the pack in fact contains considerably more. Tufts gives a similar example in which a dry food at 33% and a canned food at 8% protein both work out at roughly 36% on a dry matter basis – practically identical.

Energy: the figure often missing from a European bag

Calorie content is frequently more useful for comparing foods than percentages are, yet it is compulsory only in the United States. WSAVA points out that obesity in pets is increasing and that access to accurate caloric content helps prevent unintended overfeeding. Where the figure is not on the label, it should be obtained from the manufacturer.

An example from Tufts shows why this is no small matter: two dry foods with the same calcium percentage (1.12%) delivered 860 mg and 296 mg of calcium a day respectively – because they differ in energy density, so a dog eats far less of one than of the other. A percentage on the pack therefore does not tell you how much of a nutrient your dog will actually receive.

How much food per day?

The chart on the bag is a starting point, not a prescription. The MSD Veterinary Manual describes feeding guidelines as general recommendations at best, alongside which body weight and body condition must be monitored to prevent over- or underfeeding. Two dogs of the same weight can need noticeably different amounts.

What means nothing on a label

The WSAVA guidelines state plainly that packaging carries, alongside the required information, marketing images and phrases designed to promote sales, and that unregulated terms such as »holistic« or »premium« are of little practical value for nutritional assessment.

Every voluntary claim has to be one the manufacturer can support – if you have doubts, the FEDIAF code says to ask them for an explanation.

Questions worth asking a manufacturer

The WSAVA guidelines shift the judgement from the bag to the company behind it. Four questions matter most:

WSAVA is blunt about the conclusion: if a manufacturer cannot or will not provide this information, be cautious about that brand.

In the European Union there is a legal basis for asking. Regulation 767/2009 requires pet food to carry a free telephone number or another suitable means of communication where the buyer can obtain information about the additives and about the individual feed materials hidden behind the category names. For preservatives, antioxidants, colourants and flavourings it is enough to name the functional group, but the person responsible for labelling must disclose the details on request.

Special cases: allergies, grain free and raw food

Food allergy is rarer than the conversation suggests. According to the MSD Veterinary Manual it affects 1–2% of dogs receiving veterinary care; the most common allergens are beef, dairy products, chicken, wheat and lamb. Blood and saliva tests are not reliable for diagnosis. The diagnosis is an elimination diet – up to ten weeks may be needed to identify 95% of affected patients – confirmed by rechallenge with the original food. Set against the findings on undeclared ingredients, it is clear why this belongs with a vet rather than with a shelf in a shop.

»Grain free« is not a synonym for better. Between 2018 and 2022 the US Food and Drug Administration examined reports of dilated cardiomyopathy in dogs eating mainly grain-free diets high in peas, lentils and potatoes. It did not establish a causal relationship and, in December 2022, stopped its routine updates until more science becomes available. The sensible reading for an owner is a moderate one: grain-free food is neither forbidden nor recommended in itself, and the choice should rest on the composition and on the dog's needs rather than on fashion. If your dog has heart disease, discuss the diet with your vet.

Raw food carries a microbiological risk. In its analysis of 196 samples of raw pet food, the FDA found 15 positive for Salmonella and 32 for Listeria monocytogenes. The risk is not confined to the dog; it extends to the people in the household who handle the food. Anyone who still chooses raw feeding should treat it like raw meat for human consumption and have the ration formulated under professional supervision.

Switching to a new food

An abrupt change of food is a common cause of diarrhoea and of a refused meal. VCA recommends a gradual transition over seven to fourteen days: a small proportion of the new food at first, then a little more each day. AAHA advises the same. If loose stools, vomiting or loss of appetite appear, slow the transition down; if things do not settle within a day, call your vet.

One of the questions owners ask most often is why their dog will not eat kibble. There are several possible reasons – too fast a transition, too large a daily ration, too many treats during the day, rancid fat in an opened bag – and a sudden loss of appetite can also be a sign of illness. If a dog refuses food for more than a day, or is vomiting, listless or losing weight at the same time, this is not a question of taste but a reason for an examination.

Frequently asked questions

What is the best dog food?

One that is labelled as a complete food for the right life stage, made by a company able to answer the WSAVA questions, and on which your own dog keeps a good body condition. There is no single best brand.

What does »meat and animal derivatives« mean on a label?

It is a lawful category covering the fleshy parts of slaughtered warm-blooded land animals and the products of processing the carcass, including liver, heart and kidneys. It tells you that the material is of animal origin, but not which animal.

Is grain-free food better for a dog?

There is no evidence that it is better in itself. The FDA examined a possible link between grain-free diets and heart disease but did not establish causation; base the decision on the composition and on your dog's needs.

How do I compare dry and wet food?

Convert both to a dry matter basis: divide the nutrient by (100 − moisture) and multiply by 100. Without that step, comparing the printed percentages is misleading, because wet food is around 75–80% water.

How much kibble does a dog need per day?

Start with the chart on the pack, then adjust to your dog's weight and body condition. The MSD Veterinary Manual treats feeding guidelines as general recommendations that must be monitored and corrected.

Why will my dog not eat kibble?

Most often because the transition was too quick, the portions are too large, or there are too many treats during the day. If the dog refuses food for more than a day, or is also vomiting and lethargic, consult your vet.

Is raw food safe for dogs?

It carries a microbiological risk. Among 196 samples of raw pet food the FDA found 15 positive for Salmonella and 32 for Listeria, and the people in the household are exposed as well.

How do I know whether my dog has a food allergy?

Only through an elimination diet supervised by a vet, confirmed by rechallenge with the original food. Blood and saliva tests are not reliable according to MSD, and true food allergy is uncommon in dogs.

What does »crude ash« mean on a label?

It is not an added ingredient but the residue left after a sample is burned in the laboratory, and it mostly represents minerals. The law also permits the terms »incinerated residue« and »inorganic matter«.

In closing

A label can be read in half a minute: look for the word »complete«, the life stage, the first three ingredients, the four analytical constituents and the moisture. Everything else on the packaging is advertising. If you are choosing between two foods, convert them to a dry matter basis and ask the manufacturer for the calorie content – those two steps say more than every word on the front of the bag.

Knowing the breed helps too: the needs of a Labrador Retriever, which gains weight easily, differ from those of a German Shepherd. Every breed is gathered in the dog breed directory, and the guide on how to choose the right dog breed helps with picking one. Related nutrition guides are can dogs eat …? and foods toxic to dogs and cats.