Essential Amino Acids in Pet Food Proteins

Different proteins used in the manufacturer of dog and cat food have a varying number of amino acids and it is essential to understand the amino acids contained in various protein sources.

Types of Amino Acids:

There are two types of amino acids- essential and nonessential.

Essential amino acids cannot be made by the body and must be obtained from food sources. Nonessential amino acids can be made by the body, but it is best to get them from food sources as well.

List of 20 amino acids

Below are the 20 amino acids;

Alanine, Arginine, Asparagine, Aspartic acid, Cysteine, Glutamic acid, Glutamine, Glycine, Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Proline, Serine, Threonine, Tryptophan, Tyrosine.

There are 10 essential amino acids for dogs: Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan, Valine. Proteins that contain all of the essential amino acids in adequate amounts are considered to be “high quality” proteins.

Importance of amino acids

Amino acids are the building blocks of protein and perform a variety of functions in the body, including:

– Acting as enzymes (proteins that catalyze chemical reactions in the body)

– Building and repairing tissue

– Regulating metabolism

– Assisting in hormone production

– Boosting the immune system

– Helping to carry oxygen in the blood

Essential amino acids are important for many reasons, but some of the most important functions include:

– Building muscle tissue

– Repairing damaged tissue

– Regulating metabolism

– Boosting the immune system

Amino Acid Deficiency

A deficiency in any one of the essential amino acids can lead to a variety of health problems, including:

– Muscle weakness

– Fatigue

– Poor wound healing

– Immune system deficiency

– Hormonal imbalances

List of 10 Essential Amino Acids for Dogs

There are a total of 20 amino acids used by the body- 9 of which are essential for dogs. The 10 essential amino acids for dogs are:

1. Arginine
2. histidine,
3. isoleucine,
4. leucine,
5. lysine,
6. methionine,
7. phenylalanine,
8. threonine,
9. tryptophan,
10. valine.

The 11 essential amino acids for cats are:

1. taurine,
2. arginine,
3. histidine,
4. isoleucine,
5. leucine,
6. lysine,
7. methionine,
8. phenylalanine,
9. threonine,
10. tryptophan, and
11. valine

As you can see cats have 11 essential amino acids and cats generally have higher requirements for proteins and amino acids than dogs.

Let me explain what the amino acid is and the importance of each amino acid, starting with dog’s amino acids;

Importance of essential amino acids for dogs:

1. Histidine: This is an amino acid that helps with the growth and repair of tissue. Sources of histidine are animal protein sources such as meat, poultry, and fish.
2. Isoleucine: This is an amino acid that helps with the production of hemoglobin, which carries oxygen in the blood. Sources of isoleucine are animal protein sources such as meat, poultry, and fish.
3. Leucine: This is an amino acid that helps with the growth and repair of muscle tissue.
4. Lysine: This is an amino acid that helps with the absorption of calcium and the production of collagen (a protein that helps give structure to bones and connective tissue). Dogs get lysine from animal protein sources such as meat, poultry, and fish.
5. Methionine: This is an amino acid that helps with the absorption of copper and zinc, and the production of cartilage. Sources of methionine are animal protein sources such as meat, poultry, and fish.
6. Phenylalanine: This is an amino acid that helps with the production of dopamine and norepinephrine (hormones that affect mood). Sources of phenylalanine are animal protein sources such as meat, poultry, and fish.
7. Threonine: This is an amino acid that helps with the production of collagen and elastin (proteins that give structure to skin and connective tissue). Sources of threonine are animal protein sources such as meat, poultry, and fish.
8. Tryptophan: This is an amino acid that helps with the production of serotonin (a hormone that affects mood). Sources of tryptophan are animal protein sources such as meat, poultry, and fish.
9. Valine: This is an amino acid that helps with the growth and repair of muscle tissue. Sources of valine are animal protein sources such as meat, poultry, and fish.

How much Amino Acids do Dogs need?

AAFCO has specifications on how much of each essential amino acid dogs need in their diet and the ideal ratio of amino acids. For example, for every 100 grams of protein in a food, it should contain at least:

– 2.5 grams of arginine to puppies and min of 1.28 grams for adult dogs

– 1.1 grams of histidine to puppies and min of 0.48 grams for adult dogs

– 1.78 grams of isoleucine to puppies and min of 0.95 grams for adult dogs

– 3.23 grams of leucine to puppies and min of 1.7 grams for adult dogs

– 2.25 grams of lysine to puppies and min of 1.58 grams for adult dogs

– 0.88 grams of methionine to puppies and min of 0.83 grams for adult dogs

– 1.75 grams of methioninand cysteine combined to puppies and min of 1.63 grams for adult dogs

– Min of 2.08 grams of phenylalanine to puppies and min of 1.13 grams for adult dogs

– 2.60 grams of threonine to puppies and min of 1.2 grams for adult dogs

– 0.5 grams of tryptophan to puppies and min of 0.4 grams for adult dogs

– 1.7 grams of valine to puppies and min of 1.23 grams for adult dogs

Puppies need more amino acids than adult dogs because they are growing and developing. Adult dogs need about 18% protein in their diet, while puppies need 22-24% protein.

How much amino acids do cats need?

AAFCO has set the minimum and maximum amino acids to be included in cat food and below are the amounts required for every 100 grams of protein in a food. Cat food should contain at least;

• 3.1 grams of arginine for kittens and 2.6 g for adult cats
• 0.83 grams of arginine for histidine and 0.78 g for adult cats
• 1.4 grams of isoleucine for kittens and 1.3 g for adult cats
• 3.2 grams of leucine for kittens and 3.1 g for adult cats
• 3 grams of lysine for kittens and 2.08 g for adult cats
• 1.55 grams of methionine for kittens and 0.55 g for adult cats. Methiodine should never exceed 3.75 grams for every 100 grams of protein.

The table below shows various sources of amino acids in dog food as per the NRC research in 2006.

The Digestability of various amino acids varies with beef having amino acids that have the highest digestability. See the table below for digestability percentages in small interstines.

Protein complementation 

Some protein sources are lacking some amino acids and are complemented by mixing with other proteins with the lacking ingredients. See the table below;