Pet Nutrition: Complete or Complementary Food

For everyday feeding, choose complete food: it is formulated to meet your pet’s basic nutritional needs. Complementary food can be given as a treat or as part of the diet, but it does not replace complete food.

The difference between these types of food matters for dogs, cats, and other pets: the packaging and intended use indicate how to include a product in the diet. Let’s look at what the labels mean and how to avoid confusing staple food with a supplement.

• 2,98 млн особей cat population in Moscow in 2023
• +20% change in the cat population in Moscow in 2023 compared with 2020
• 1,4 млн dog population in Moscow in 2023
• +13% change in the dog population in Moscow in 2023 compared with 2020

How is complete food different from complementary food?

Complete food is formulated to provide a cat with energy and all essential nutrients in the required amounts and proportions; complementary food is not. That is why complete food can be a cat’s sole food, provided it is specifically formulated for cats.

• Complete food: suitable as the basis of a diet if the packaging says the food is complete or carries an equivalent label.
• Complementary food: does not meet a cat’s needs for all essential nutrients in the right amounts and proportions, so it should be given as a treat, not instead of staple food.

When choosing a product, check its intended use on the label, including the animal it is for and whether it is complete. For example, a can or pouch labelled “complementary food” does not become suitable as the basis of a diet just because a cat enjoys eating it.

How can you tell from the label whether a food is suitable as the basis of a diet?

What to look for on the packaging

To find out whether a food is suitable as the basis of a diet, look for the word “complete” or an equivalent label on the packaging, and check which animal the product is intended for. These two features matter more than whether the food is dry or wet.

• Product type. Look for the word “complete” or a synonym: this food is formulated to provide your pet with energy and essential nutrients. If the product is labelled as complementary, it does not replace staple food and is better suited as a treat.
• Animal type. Check the intended use on the packaging: cat food should not be chosen as the basis of a dog’s diet, or vice versa. The stated animal must apply to the specific product.
• Form and presentation. A wet texture, convenient single-serve packaging, or the fact that your pet enjoys the food does not prove that it is complete. For example, wet food can be either complete or complementary—the label tells you which.

Assess the packaging as a whole: check the food’s intended use first, then the animal it is for. If the product is intended for your pet and labelled complete, you can consider it as the basis of their daily diet; palatability and convenience do not change that.

Why is it important to check the label on every product?

It is important to check the label on every product so you can distinguish food suitable for a staple diet from a treat: complete food provides energy and essential nutrients in the amounts a cat needs, while complementary food does not supply them in the right amounts and proportions. These products can look alike, so go by the label on the packaging, not by the food’s appearance or format.

The number of pets in Moscow shows how many animals live in the city, but it does not determine what they should be fed. In Moscow in 2023, there were 2,98 млн cats—20% more than in 2020. In Moscow in 2023, there were 1,4 млн dogs—13% more than in 2020.

What to look for on the packaging

• Complete food: look for the word “complete” or a synonym on the label. This product can be a cat’s sole food.
• Complementary food: treat it as a snack, not a replacement for staple food: it may not contain enough essential nutrients, or they may be present in unsuitable proportions.

What happens if complementary food becomes the main food?

If you regularly give your pet complementary food instead of complete food, you cannot be sure they are getting all the essential nutrients in the right amounts and proportions. This product can be offered as a supplement, but it is not formulated to be the sole food—unlike food labelled “complete.”

A common mistake

Complementary food does not become a complete diet just because your pet particularly likes it or it is convenient to serve. For example, a treat or complementary wet food does not replace food labelled as complete: the product’s intended use is determined by its label, not by the animal’s appetite.

• “Complete” — the food is formulated as a staple diet and contains essential nutrients in the required amounts.
• “Complementary” — the product is meant to be added to the diet, not to regularly replace complete food.
• Unclear intended use — check the label or ask the manufacturer whether the product is suitable as the sole food for everyday feeding.

If you are unsure, choose a product labelled “complete” or with an equivalent term on the packaging. This is especially important when the food is a staple, rather than an occasional treat.

Can you combine staple food and treats?

Yes, you can combine complete food with complementary food: the first forms the basis of the diet, while the second is given as a treat. Complete food is formulated to provide your pet with energy and essential nutrients in the required amounts; complementary food is not.

Complementary food does not replace staple food: if you feed it instead of a complete product, the diet may not provide the required range of nutrients. So choose staple food based on the “complete” label or an equivalent marking on the packaging, not on whether the product is dry or wet.

How to check the packaging

• For the basis of the diet: look for the word “complete” on the label or a statement that the product is intended for complete everyday feeding.
• For a treat: complementary food can be given separately, but should not be used instead of staple food.
• If the category is unclear: before feeding, check the product’s intended use on the packaging or with the manufacturer. Do not assume food is complete just because it is dry or wet.

What simple rule can help you choose food?

For a staple diet, choose food labelled “complete” or with an equivalent term; reserve products marked “complementary” for treats. This rule helps you distinguish foods by their intended use, not their appearance.

• “Complete” — this food is formulated to provide your pet with energy and essential nutrients as their staple food.
• “Complementary” — use it as a treat, not as a replacement for staple food: it does not contain all essential nutrients in the required amounts and proportions.

Whether it is dry or wet, in kibble or chunks, the form and packaging alone do not show whether the food is complete. For example, wet food may be intended either as a staple diet or as a treat, so check the label on the specific can or package.

Before buying, read the label on the specific product you have chosen and check its intended use. If the food is offered as your pet’s sole food, look for the “complete” label or an equivalent term; a “complementary” label means it is not suitable as the basis of the diet.

Key takeaways

• The basis of a diet should be food labelled “complete” or with an equivalent term.
• Complementary food is intended as a treat, not a replacement for staple food.
• Wet or dry form alone does not determine whether food is complete.
• Before feeding, check the intended use of the specific product on its packaging.

Frequently asked questions