Dog Nutrition (I): Proteins

Proteins are a class of organic compounds that can be found in every living cell. They contain carbon, hydrogen, nitrogen, oxygen and sulfur. Proteins are vital for humans and for any other living creature. The body depends on proteins for a variety of functions such as: locomotion, creating hemoglobin, carrying oxygen. The structure of the cells is largely made of proteins.

The proteins are made of one or more chains of amino acids. When consumed, the proteins are broken down into basic units – amino acids – by the digestive system so they can be reused to create or recreate tissues, muscles, bones, blood and other cells. Some of the amino acids are created by the body itself (non-essential amino acids), whereas others can only be obtained by eating protein rich foods (essential amino acids).

For dogs, the essential amino acids which must be supplied in the diet are: Arginine, Methionine, Histidine, Phenylalanine, Threonine, Tryptophan, Lysine, Valine, Isoleucine and Leucine.

• Arginine is essential to dogs, being required for proper functioning of the blood vessels. A shortage of this amino acid can cause heart and kidney problems.
• Histidine is an amino acid that widens small blood vessels and that is associated with pain control and arthritis.
• Lysine is an essential amino acid which promotes bone growth in puppies, stimulates secretion of gastric juices, and is found in abundance within muscle tissue.
• Methionine is the amino acid assists that prevents deposits and cohesion of fats in the liver, balances the urinary tract and gives rise to Taurine (an important neuroregulator in the brain).
• Phenylalanine stimulates chaleceptokinin enzymes and thus is related to appetite control, increases blood pressure in hypotension and works with minerals in skin and hair pigmentation.
• Threonine regulates energy draw requirements, works with Phenylalanine in mood elevation or depression and skin pigmentation, manufactures adrenalin, and releases Thyroid hormone.
• Tryptophan produces Serotonin that induces sleep, precurses the vitamin Niacin in treating and preventing pellagra, and is a vasoconstrictor that appears to aid in blood clotting mechanisms. Studies indicate a lack of tryptophan and methionine together can cause hair loss.
• Valine, Isoleucine and Leucine work together and combine to regulate the protein turnover and energy metabolism. They are stored in muscle tissue and are released to be converted into energy during times of fasting or between meals.

There are many sources of proteins, some of them considered balanced or complete (if they contain both essential and non-essential amino acids) and some not. It’s essential for a balanced dog nutrition to receive proper amounts of both essential and non-essential amino-acids. One missing amino-acids can keep dogs from being healthy.

Proteins can be found in beef, poultry, fish, eggs, dairy products, nuts, seeds, and legumes like black beans and lentils. Eggs, muscle and organ meats are the most complete and digestible sources of protein and should be part of your dog’s menu. The digestibility is also important because, after all, it doesn’t matter the amount of food if the proteins in it are not digestible. For instance, grains and vegetables have proteins but they are less complete and less digestible.

Dogs should have meals based on protein-rich foods and, consequently, the low-quality commercial dog foods should be avoided as most of them are based on grains and other by-products. Pet companies use strong advertising strategies that can mislead people into thinking a low-protein diet is good for their dogs. It’s not! Unless they have health problems like an illness requiring restricted amounts of proteins, dogs should be fed high-protein meals in order to maintain their tissues, muscles, bones and proper functioning of the body.

How Much Protein Should I Feed My Dog?

Dog diets should have 20%-30% protein in their meals. Dogs fed diets too low in proteins may develop deficiency symptoms like decreased appetite, poor growth, weight loss, a rough and dull coat, and decreased immune function. Extra proteins are usually metabolized and used for energy. They are not stored in the body like fats are. However, excessive amounts of energy can be used for producing fats. So, even if the connection is indirect, too many proteins can make your dog fat.

There is a common myth that dogs get hyperactive or aggressive if they have high-protein diets but there is no scientific proof in support of this idea. There is also no evidence that excessive proteins can contribute to the development of kidney dysfunction. A moderate protein content diet can be used only for puppies (especially large breed) to ensure a slower growth and to avoid orthopedic problems.

That’s about it! The next post will be on Carbohydrates! Enjoy!