11 Jul 2022

Proteins in Pet Food

What are proteins and why are they important in the diet of cats and dogs? What are they made of and where are they sourced from? Is it possible to compare the protein content of different pet food products? Is higher protein percentage on the label an indication for a better product? Here you will find detailed responses to these common questions.


What are proteins?

Proteins are essential macro-nutrients that act as building blocks in living tissue, such as muscles and organs of all living creatures, and can produce energy when digested. Proteins also have functional roles (e.g. enzymes, hormones, and antibodies) in vital processes in the body and therefore need to be consistently replaced. This can be accomplished by regularly consuming foods that contain protein.

Structure of proteins

Proteins are large molecules made up of much smaller units called amino acids. Although only about 20 different amino acids are found in dietary proteins, the number of sequences in which they can be arranged is vast. This results in the wide variety of proteins found in nature.

Proteins in Pet Food

Proteins are required in the diet of all pets, including dogs and cats. Still, each species of animal will need different amounts and types of amino acids, and the recommended amounts may vary for different breeds and life stages. While proteins can be sourced from different origins (animal and plant-based)1, the pet's amino acid requirements need to be met. Fediaf Nutritional Guidelines indicate minimum and maximum levels of nutrients, including amino acids, needed in cats’ and dogs’ diets. Maximum levels are detailed in the Fact Sheet.

Understanding the "protein percentage"

It is a legal requirement to show the protein percentage as well as fat, fibre, ash and moisture under Analytical Constituents on pet food labels. However, it is impossible to compare the protein levels of different products unless we work out how much protein the animal is consuming (i.e. grams of protein per day), taking into account feeding amounts as well as the water content of the product. Please see the factsheet for how this equation is conducted.

Comparing protein levels of wet and dry pet food based on Dry Matter

To compare the percentage protein of wet (refers to commercially raw and cooked pet food products with a water content of 60% or more) food and dry food, we need to allow for the fact that wet food contains much more water.

Protein levels in pet food

Any food containing high levels of water will declare relatively low percentages of proteins, fats, etc., compared to dried food, but as you feed more of the wet product, your pet will receive the required nutrients. Wet food is made of around 60-80% water, and the rest is called ‘dry matter’, which includes all the nutrients. A direct comparison of nutrients in a wet and a dry product is impossible unless a dry matter comparison is conducted.  Our fact sheet highlights how to work out these equations.

How daily feeding amounts determine protein levels for dogs

It is important to allow the feeding guide to determine exactly how much protein an animal gets from its food. If you compare two dry dog foods, not only may they have different protein percentages, but they could also recommend different feeding amounts.

Use the conversions in our factsheet to work out the actual amount of protein your dog is consuming on a wet or dry diet.