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?
In this section you can find out the answer to these questions and more in our Protein Factsheet, which is free to download and print.
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 there are only about 20 different amino acids 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.
Quantity and quality of proteins
Proteins are required in the diet of all pets including dogs and cats, but each species of animals will need different amounts and different 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, it is the amino acid requirements of the pet that needs 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 not possible to compare the protein levels of different products unless we work out how much protein the animal is actually consuming (i.e. grams of protein per day), taking into account feeding amounts as well as the water content of the product. Please see fact sheet 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 a wet (refers to commercially raw and cooked pet food products with a water content of 60% or more) food and a dry food, we need to allow for the fact that a 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 that of a dried food, but because 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 not possible unless a dry matter comparison is conducted. Our fact sheet highlights how to work out these equations.
How daily feeding amounts determine protein levels
It is important to allow for the feeding guide to work out exactly how much protein an animal gets from its food. If you compare two dry dog foods, not only may they have differing protein percentages but they could also recommend different feeding amounts. In order to work out the actual amount of protein the dog is consuming on a wet or dry diet, you must do the conversion as detailed in our factsheet.