Sunday, November 23, 2008

Canine Protein Requirements: Too much or not enough? Part 4a

Can you feed too much protein? The answer to this is yes and no. Theoretically, if a healthy animal eats too much protein, some gets excreted in the urine and the rest just gets used as calories or is converted to fat and does not cause any harm. However, if your dog has a kidney problem, a diet rich in protein is not recommended. Another factor is that, next to marketing, protein is the most expensive ingredient in the food. Why should you pay for more than you need? Most pet food companies strike a happy medium and meet the minimum recommended requirements plus a small safety cushion.
Following here today and in subsequent parts are various view points on this controversial topic explained by their expert owners:
Steve Brown in his book “See Spot live longer”, a part science, part practical advice on helping dogs live longer based on the thesis of “proper raw diets”, says:
“The natural diet of the dog is high in protein. Almost everything the dog ate in the wild was high in protein, high quality animal protein.” Steve calculated from information he found in the “Diet of Ferral Carnivores” that the typical diet of a dog consisted of 56% protein on a dry matter (DM) basis. He goes on: “The protein content of most dry foods ranges from 20% to 30% on a dry matter basis. Much of this protein is low quality protein from grain. In a typical “premium “ lamb and rice product, for example, 26% is lamb and 63% is grain.”
Further down in his chapter he shows protein content values of dog foods in comparison (Dry matter): Rabbit 80%, Natural diet 56%, Commercial raw diet 45+% and Dry foods 20 to 30%.
Steve continues: “Dogs need meat, not grain. While some dogs live quite well on high carbohydrates diets, many do not. Our goal with this book is to increase the odds that all our dogs will live long healthy lives. Dogs need a meat based diet, preferably raw, to do this. The pet food industry is continually learning more about the need for meat and high quality protein. This is especially true for cats. A 2002 article in the Journal of the American Veterinary Medical Association concluded: “although cats have adjusted to most manufactured diets, the limitations of substituting animal origin nutrients with plant origin nutrients in foods formulated for cats are being increasingly realized. “ After a few short comments about taurine deficiencies in commercial dry foods for cats, which, since this is an article about canines, I decided to skip, he says: “We are now learning that the lack of taurine in the diet may be creating heart problems with some dogs fed lamb meal and rice or tofu based diets. Scientists at the University of California, Davis, world leaders in understanding feline nutrition (and therefore experts in taurine) report: “Diet related taurine deficiencies and associated dilated investigators have recently reported taurine deficiency (52%) and cardiac insufficiency (10%) among a group of 21 privately owned Newfoundland dogs”. It’s not just large breeds that may have taurine deficiency problems on lamb and rice diets. The Amerian Cocker Spaniel is well known to have taurine and carnitine responsive dilated cardiomyopathy.”
Three of Steve’s own dogs died of heart problems (the reason why Steve wrote his book), all were eating a major national brand lamb and rice diet.
Several dog food manufacturers are now adding taurine to their lamb and rice diets to help correct this issue. According to Steve “L-canitine: Evidence indicates it may accelerate weight loss and increases lean body mass” is the ride of an article by Tim Phillips, DVM and Editor of “Pet Food Industry” in his May 2002 issue. He continues: “Carnitine deficiency is a proven cause of heart disease in dogs…. Most pet foods are relatively low in L-carnitine due to the type of ingredients used. Even though L-carnitine is present in both, plant and animal ingredients, ingredient processing removes significant amounts of it. Wild type diets for dogs and cats (like meat or whole carcass) provide significantly more L-carnitine than commercial pet foods. Controlled studies with sled dogs show that those dogs fed diets high in fat and protein and very low in carbohydrates outperform those fed moderate or high carbohydrate diets.”
Steve conclusion is: “Not all proteins are the same. Proteins are very large molecules that consist of chains of hundreds of much smaller sub units called amino acids. There are 22 types of amino acids. Animals need dietary protein to provide the specific amino acids that their tissues cannot synthesize. Essential amino acids are those that cannot be made by the body in sufficient quantities and must be supplied in the dog food. High quality proteins, like eggs and most meats, consist of a full range of these essential amino acids. Low quality proteins, like the protein in most grains, consist of only some of the essential amino acids. Animal proteins generally have a more balanced amino acid profile and better digestibility than plant proteins. Protein quality is often measured in biologic value, the percentage of the protein that is absorbed and retained, not excreted. The higher the biologic value, the better the quality of the protein. Meats have much higher biologic values than grains. For example the biologic value of beef is 78%, corn is 45%.
What a radical change: In just 50 years the dog’s diet changed from high quality, high quantity protein to low quality, low quantity protein.”

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