Proteins / Amino Acids
Proteins are made up of different amino acids; amino acids are essentially the building blocks of proteins. Proteins can be divided into simple proteins (which consist solely of amino acids) and complex proteins (which contain a simple protein plus a molecule that is not a protein).
The intestinal wall cannot absorb proteins because they are too large. Therefore, proteins must first be broken down into smaller pieces, the aforementioned amino acids. These amino acids can then be absorbed through the intestinal wall.
Proteins have various functions in the body of a dog or cat; proteins are needed for:
- The skin and coat: the skin and coat are largely made up of proteins. Proteins are the basic component of the skin, coat, and nails.
- Body tissue/Connective tissue: the connective tissue of the body largely consists of collagen, a protein.
- The muscles: various proteins are needed for muscle function.
- Digestion of food: enzymes required for food digestion are protein molecules.
- Hormones: various hormones in the bodies of dogs and cats are made up of proteins.
- Transport: proteins in the blood are responsible for transporting substances.
- Acid-base balance: besides their role as transporters, proteins in the blood are also needed to regulate the acid-base balance in the body.
- The immune system: antibodies that protect the body against harmful microorganisms from outside consist of protein molecules.
When you look at the above functions of proteins, you can imagine that proteins are essential for dogs and cats. Without proteins, dogs and cats cannot survive.
However, not all proteins/amino acids are essential for the animals. Amino acids can be divided into essential and non-essential amino acids. Essential amino acids must be obtained by dogs or cats through their diet. Non-essential amino acids can be produced by the body of a dog or cat from other nutrients. Below you will find the essential amino acids for dogs and cats:
|
Essential for dogs |
Essential for cats |
|
Arginine |
Arginine |
|
Histidine |
Histidine |
|
Methionine |
Methionine |
|
Phenylalanine |
Phenylalanine |
|
Threonine |
Threonine |
|
Isoleucine |
Isoleucine |
|
Leucine |
Leucine |
|
Lysine |
Lysine |
|
Tryptophan |
Tryptophan |
|
Valine |
Valine |
|
Taurine |
The protein requirement of a dog is different from that of a cat. Dogs need less protein than our little house tigers. Additionally, cats are obligate carnivores, which means that certain essential proteins cats need are only found in animal material (meat).
The protein nutritional requirement is not only species-dependent. The life stage of an animal also plays a role in protein needs. For example, younger animals that still need to grow have a greater need for proteins than adult animals. Pregnant, lactating, and working animals also have a higher protein requirement.
Proteins can come from plant or animal sources. Animal proteins generally have a higher biological value than plant proteins. This means that animal proteins contain more essential amino acids in amounts that match the amino acid needs of a dog or cat than plant proteins (however, this does not mean that plant proteins are not useful for dogs and cats).
