Sustainable Dog Food and Cat Food Buying Guide

Written by: Richard Rowlands

Protein is one of the most important nutrients in pet food, and an essential part of a healthy diet for cats and dogs. In this article, we'll explain the role of protein in the body and why it's important for your pet's health. We'll also take a look at the different kinds of protein found in the best natural cat food and dog food, and explore why many pet food manufacturers are using sustainable proteins in their products.

Why Does My Pet Need Protein?

Alongside carbohydrates and fat, protein is one of three essential macronutrients that are required by the body. Proteins consist of chains of amino acids. These amino acids perform vital functions in the body, including repairing tissues, building muscle, regenerating cells, and producing hormones. When proteins are digested, they are broken down into amino acids by the digestive system. The amino acids then enter the bloodstream to be utilized by the body.

There are two types of amino acids: Non-essential and essential. Non-essential amino acids are produced by your pet's body. By comparison, essential amino acids must be obtained through diet. Cats and dogs require 10 essential amino acids: arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. In addition, cats require an extra essential amino acid called taurine (with evidence mounting that some breeds of dogs are susceptible to taurine deficiencies and related heart issues). These essential amino acids are found in protein-rich foods such as meat, fish, eggs, and some plant-based foods.

How Much Protein Does My Pet Need?

The amount of protein your pet needs will depend on several factors, including their age, size, breed, and activity level. The quality of the protein in your pet's diet is also an important factor. Puppies and kittens, pregnant or nursing mothers, and working animals have higher protein requirements than normal adult animals. Since cats are strict carnivores, they require significantly more protein in their diet than dogs.

A lack of protein in your pet's diet can lead to a number of health problems, including poor skin and coat health, weight loss, digestive issues, and reduced lean body mass. Excess protein in a healthy pet's diet would typically be excreted in the urine or used as energy. However, consuming too much protein could potentially cause your pet to gain weight. Thankfully, the best natural dog foods and cat foods contain adequate protein levels to support your pet's nutritional needs. We recommend consulting with your veterinarian to discuss your pet's specific protein requirements.

What Types of Protein Are in Pet Food?

High-quality pet foods contain a variety of different protein sources. In this section of the post, we'll take a look at a few of the most common.

Animal-Based Protein Sources

Animal-based proteins contain the most complete and easily digestible amino acids for dogs and cats. Some of the most common animal-based protein sources used in pet food include chicken, beef, lamb, and fish.


Chicken is a great source of lean protein that helps build lean muscle and delivers beneficial omega-6 fatty acids and essential amino acids. Look for pet foods that contain organic, cage-free, or free-range chicken from a reliable source.


Beef is an excellent protein source that's rich in iron and B vitamins. The best pet foods are made from whole cuts of beef. Avoid foods that contain unnamed or beef byproducts. These low-quality ingredients are made from the discarded parts of the carcass.


Lamb is a nutrient-dense food that's packed full of essential amino acids and healthy fats. It also contains vitamins and minerals that support your pet's overall health. We recommend choosing a pet food made from whole cuts of lamb, rather than lamb byproducts.


Fish is high in omega-3 fatty acids, essential amino acids, and lean protein. It is also highly digestible and low in fat. Salmon is especially healthy for pets. It contains vitamins A, D, and B, along with beneficial minerals including zinc and magnesium. Always look for wild caught fish from MSC certified fisheries.

Plant-Based Protein Sources

Plant-based ingredients are good secondary sources of protein in your pet's diet. For this reason, they are often used in combination with meat-based proteins in premium pet foods. Some of the most common plant-based proteins found in pet food include legumes, pulses, and grains.

Legumes are the fruits or seeds of plants belonging to the Fabaceae plant family. Examples include beans, lentils, peas, and chickpeas. Pulses are the dry, edible seeds of certain legumes. Common pulses found in pet food include dried peas, dried beans, and lentils. Not all legumes are pulses, but all pulses are legumes. Grains are the seeds of cereal crops that are grown as food. Examples include oats, barley, quinoa, and other ancient grains.

What Are Sustainable Proteins?

As pet parent-ship becomes more and more popular, there's an increasing need for protein sources that are sustainable and environmentally friendly. For this reason, more and more pet food manufacturers are using sustainable proteins in their products. In this final section of the post, we'll highlight a few of these emerging protein sources.

Sustainable Plant-Based Proteins

Yeast is a popular, vegan protein source for dogs. Algae and duckweed are two examples of sustainable plant-based proteins that are used in pet food. These aquatic plants can be grown on water year-round. They have a high amino acid concentration and can thrive in areas where other crops cannot be grown.

Small Fish

Small fish like herring, sardines, anchovies, and even minnows are a great source of protein, omega-3 fatty acids, vitamins, minerals, and other nutrients. They are very sustainable and are lower in common heavy metals in larger fish, like mercury.

Sustainably Caught Fish

Larger fish, like salmon, whitefish and tuna are packed with health nutrients for your pets. But make sure you look for wild caught or MSC certified fish.


Insects such as fly larvae, crickets and mealworms are low in fat and high in protein. They are also a good source of fatty acids, vitamins, and minerals. Insects are easy to breed and cultivate, can be raised on human food waste, and are far more sustainable than traditional meat-based protein sources. According to an article from the BBC, "Protix, a Dutch firm which claims to have the world’s biggest insect farm, estimates that compared with beef, insect-based foods use 2% of the land and 4% of the water per kg of protein."

Looking for high-quality pet foods made with sustainable ingredients? Check out our range of sustainable pet food and treats.

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