There is a lot of misconceptions concerning protein and dogs. So let’s start with the basics and learn exactly what protein is and what foods contain the necessary proteins for a healthy dog's diet.
Proteins are made up of amino acids. Each amino acid is important because of the specific way it contributes toward healthy nutrition. The amino acids contribute to important and necessary chemical processes that keep dogs healthy. For instance, carnitine and taurine are necessary for heart health. L-glutamine helps repair and build muscles. Arginine helps keep blood vessels dilated and stimulates the immune system. Lysine helps with bone growth and absorption of calcium. Cysteine helps in skin tone and elasticity, and is required to manufacture taurine. There are two types of amino acids: essential and non-essential. In order for essential amino acids to be available for dogs to assimilate and use, they must be present in the foods dogs consume. The non-essential amino acids can be supplied in the diet or the dog’s body can synthesize them.
Essential Amino Acids
Arginine, Histidine, Isolueucine, Leucine, Lysine, Methionine, Phenylalanine, Tryptophan, Threonine, Valine and Taurine*
*Taurine has been considered a non essential amino acid in dogs, but recent studies have indicated that it may likely be conditionally essential.
Non-essential Amino Acids
Alanine, Asparagine, Aspartate, Carnitine, Cysteine, Glutamate, Glutamine, Glycine, Lycine, Hydroxlysine, Hydroxyproline, Proline, Serine and Tyrosine
With these in mind, understand that not all proteins are equal. While carbohydrates do contain and offer some protein value, they are missing the essential amino acid, taurine. Additionally, many plant sources lack lysine, arginine, methionine and tryptophan. While we as humans are omnivores, dogs are carnivores. They need all the amino acids offered by animal based sources, which include meat, organs, dairy and eggs. The amino acids from plant sources are incomplete for dogs, and unless the amino acids from animal based sources are present in the diet, serious nutritional deficiencies can occur. Plant sources include grains, fruit and vegetables. Additionally, cooking food at high temperatures (which is done during commercial dog food processing) also destroys some amino acids. When these amino acids are destroyed the dog's body craves them, which results in your dog requiring more protein to thrive and maintain good health.
Now that we know what proteins are and how much dogs need them for good health, let’s look at some 'mistaken' information on when to reduce proteins.
Dog owners are often advised to reduce protein for senior dogs. This is false information. Senior dogs (and humans) have a more difficult time digesting, metabolizing and storing proteins. For this reason, older dogs need not only more protein in their diet, but higher quality proteins. Higher quality proteins are easier to digest, and offer the amino acids needed for good skin, coat and organ health. Senior dogs often require more protein than adults.
Most liver problems do not require a reduction in protein. Amino acids are important in keeping the liver in good health and helping a compromised liver repair itself. If the dog has a shunt condition, certain proteins do need to be avoided and these would include red meats and organ meat. These contain higher amounts of ammonia which are to be avoided with shunt disorders. However, eggs, yogurt, cottage cheese and occasionally poultry can be used as protein sources for these dogs.
Oftentimes dog owners are told to reduce protein in the diet if kidney disease is suspected. They are often told reducing protein will prolong the health of the kidneys. But new studies have found this is not exactly true. It isn't reducing protein that helps, but rather reducing the phosphorus (a part of protein) levels that help. However, reducing phosphorus isn’t helpful until the renal values in the blood work show elevations in creatinine and BUN. A general rule of thumb is when the BUN values go over 80, and creatinine levels are over 2. Along with these two levels, indications of the kidneys inability to handle phosphorus also results in an elevation in the phosphorus level. At this time, reducing phosphorus will help with comfort as less phosphorus will be filtered through the kidneys. High phosphorus foods include bone, organ meat and egg yolks.
So before jumping the gun and reducing protein (necessary nutrients for good renal health), check the blood work to determine when you might start needing to reduce the level of *phosphorus*. For dogs being fed a raw diet, lowering phosphorous levels might mean removing bones and organ meat and adding carbohydrates for fiber (firm stools). For those feeding home cooked diets for your dog, it may mean removing organ meat and egg yolks and using low phosphorus carbohydrates. Don’t reduce the *quality of protein,* simply reduce the level of phosphorus.
Important Note on Kidney Disease and Diagnosis:'
Should your dog receive a kidney failure diagnosis, always run tests for problems that could cause ‘acute’ renal issues (treatable). Understand that ‘old age’ does not cause renal failure. Some tests to consider include: sterile urine culture for urinary tract infections, leptospirosis blood titer, blood work and ACTH stim test for Cushing’s and Addison’s Disease and a blood test for Tick Borne Diseases. All of these can cause elevations in BUN, creatinine, low specific gravity, and protein in the urine.
While I have rarely heard of any recommendations to reduce protein for dogs with heart problems, it is more important than ever to give good, high quality proteins for this problem. Taurine and carnitine are important for heart health, and these amino acids are found in meat. Remember, high heat can destroy these amino acids, so use raw or lightly cooked meat. And the best source for these two amino acids is heart itself such as pork, lamb, beef and chicken hearts. These are an excellent food source for dogs with heart problems. Remember, heart is a muscle meat, *not* an organ meat, so heart can be fed daily as a large part of the diet.
So, what is the answer to the question of when to reduce proteins? Practically never! On occasion, it may be necessary to reduce phosphorus in chronic renal failure, or change protein types in liver shunt issues and in food allergies. But lowering protein amounts in the dog’s diet removes much needed nutrients for organ health, skin and coat, immune system and the ability to thrive.
Dr. Olson has a wonderful, informative book called Raw & Natural Nutrition for Dogs. She also has a newsletter filled with great info that you can sign up for at her website: b-naturals.com. It has recipes for transitioning and feeding a raw diet, as well as history on the commercial dog food industry that will really open your eyes! It is one of the books, as the nutritionist for Animal Nutrion Solutions Canine Consulting, that I recommend to all of my clients for continuing education. It is important for the consumer to understand how and why the dog food industry thrives, and to educate themselves that there are better choices for their dogs.