The truth is dogs and cats do not need any protein in a healthy state at all. What they do need is the building blocks of protein. Even if animals ingested their exact daily requirements of protein, their alimentary tract would still break the proteins down to individual amino acids through the process of digestion. There are 22 amino acids that their bodies require. They can synthesise 12 of them.
Essential to maintain life
Proteins are used in the animal as structural components in skin, hair, muscle and organs. They are the major components of enzymes and some hormones essential for maintaining life. Proteins are able to provide carnivorous animals with energy. They also form a vital part of an animal’s immune system.
Must be in their food
Dogs and cats, being carnivorous animals, are well adapted to digestion of meat sources, which contain all their essential amino acids. An alternative way is to supplement food sources that contain inadequate amounts of these essential amino acids. The most well-known example of this is taurine supplementation to non-meat based cat foods. Kittens, puppies and aging dogs and cats actually have the highest requirements of essential amino acids. The best examples of inadequate essential amino acid and caloric ingestion can be seen in older animals, where the shapes of their bones start to be visible because of a loss of muscle mass.
The body will utilise its own muscle mass for essential amino acids if ingestion of these nutrients is inadequate. This loss of lean muscle mass is best seen over the head, spine, shoulder blade and hip area. Sometimes these animals even have excess body fat.
Cats need more
The actual protein requirement of the cat is higher than that of the dog. This is a result of cats’ greater need for protein for the maintenance of normal body tissues and the inability to down-regulate certain catabolic enzymes in the liver used to convert protein to energy, regardless of what other source of energy is provided in the food.
Biliary tract protection
As mentioned earlier, animals also gain important by-products when proteins are broken down for energy. Another example of this is the molecule phosphotidyl choline, which protects an animal’s biliary tract from the caustic action of its own bile. Bile is important in food digestion and if the biliary tract, which is also food, is not adequately protected, biliary tract damage will ensue.
How much protein?
The amount of protein that an animal needs to ingest in order to obtain adequate or optimal amounts of essential amino acids and energy, varies with the protein source’s digestibility and with the protein’s actual content of all of the essential amino acids. As the protein digestibility and quality increases, the minimum level of protein that has to be included in the diet to meet the animal’s needs decreases.
In general, high-quality animal source proteins provide superior amino acid balances for companion animals when compared with amino acid balances supplied by grains or other plants.
Text: Dr Martin de Scally, small animal veterinary specialist
The full article appears in the Arpil issue of AnimalTalk.