"I am very interested in the evidence you have to support those conclusion"
CANINE NUTRITION: A Practical Approach to Feeding Dogs and Puppies THE CONTROVERSY OF CANINE NUTRITION Want to incite a riot among an otherwise amiable group of dog breeders, commercial nutritionists, veterinarians and pet food salespersons within a relatively short amount of time? Begin a conversation about which brand of dog food one should be feeding their puppy or adult dog. Among dog breeders, brand of food is an extremely sensitive topic, mainly because many breeders base their evaluation of dog food on many years of experience and performance among their dogs. In many cases, the best dog food isn't always the most expensive or the most socially acceptable dog food on the market. At the heart of the controversy, many nutritionists and pet food salespersons take the stand that puppies require expensive, specially formulated high protein, calorie-dense diets to maximize skeletal development. However, clinical research on the occurrence of skeletal diseases in growing dogs have veterinarians and canine orthopedic specialists taking the opposite side that high plane nutrition increases risk of skeletal diseases in medium and large breeds predisposed to developmental bone disorders (including hip dysplasia, osteochondritis dessicans, panosteitis, hypertrophic osteodystrophy, etc.). To minimize occurrence of these disorders, they recommend that foods encouraging rapid and maximized growth in puppies be avoided with the premise that a gradual, progressive growth curve obtained through restriction of high-calories and avoidance of rapid weight gain, particularly between the ages of 4-8 months, ensures less stress on developing joints and bones. The following article addresses the nutritional requirements of the dog for the purpose of selecting good-quality dog food. Additionally, common misconceptions regarding feeding and supplementation are discussed in regard to medical findings. DETERMINING NUTRITIONAL FOOD REQUIREMENTS OF THE CANINE Dogs are considered carnivores--meat eaters--however, to acquire complete nutrition, a dog must eat a wide variety of cereals and vegetables as well as meat. Therefore, meat-only diets, particularly those which must be supplemented with excessive amounts of vitamins and minerals are not recommended since they often do not provide the critical balance of nutrients required. To take the guess-work out of canine nutrition, recommendations for the daily nutrient intake for proper growth and maintenance of dogs is outlined by the "National Reasearch Council's Nutrient Requirements of Dogs (NRC). " The latest NRC publication provides a guideline for the manufacturing of good-quality commercial brand dog foods. However, dog food labels are misleading because although many of them claim to meet or exceed NRC recommendations for nutrients, the quality and thus the digestibility (bioavailability) of these nutrients are often undetermined in these dog foods. Therefore, a more reliable assurance of nutritional quality is given by labels that state that the food has passed American Association of Feed Control Officials' (AAFCO) feeding trials. IS THERE "ONE" BEST BRAND OF DOG FOOD ? Unfortunately, there is no one superior brand of dog food on the market which will work best for all dogs. This is primarily because nutritional requirements differ from dog to dog based on factors related to breed, genetics, body weight, level of activity, environment, pregnancy or lactation, and age. It is, therefore, important to take these factors into consideration when selecting a commercial dog food that will provide the necessary levels of protein, fats, vitamins, and minerals. When acquiring a puppy from a breeder, it is recommended that the brand of dog food and feeding guidelines be discussed with the breeder. Unlike dog food salespeople who have a vested interest in selling expensive dog foods, breeders usually recommend dog food based on years of experience with the performance of their own dogs on a particular brand of dog food. If a breeder is pleased with a particular brand of dog food, it is usually because her dogs have exhibited signs of good health and nourishment while on that brand. Such signs include alertness, vigor, good appetite, regular urination and defecation habits, proper weight, glossy haircoat, unblemished skin, and bright eyes and indicate that a dog food is providing the necessary nutritional requirements. Sometimes, however, advice pertaining to dog food may not be available from a breeder. In such cases, pet owners may have to make decisions based on little or no experience. Therefore: WHAT FACTORS ARE IMPORTANT WHEN SELECTING A BRAND OF DOG FOOD? PROTEIN Proteins contain essential amino acids which are the building blocks for growth and repair of the body. The average dog requires a minimum of 22% protein in dry dog food for basic maintenance; higher levels are required in pregnant or lactating bitches. Unlike fat, very little excess protein is stored by the body. Most excess protein is degraded and excreted by the kidneys. (Therefore, feeding expensive, high-protein performance dog foods to the average dog is equivalent to "urinating"-away money!) Dogs, however, with high daily energy requirements, such as working dogs, require higher protein levels. In this case, high performance dog foods are required because they are specially formulated with highly digestible sources of protein to provide energy requirements and prevent protein depletion. It is important to note, however, that high protein content listed on a dog food label does not guarantee a nutritional advantage. Nutritionally, the source of dietary protein is perhaps more important than the percentage of crude protein listed on the side of the bag. Animal protein sources (meat) are better than plant protein sources (soy). Therefore, a dog food claiming 28% crude protein derived from soy, would not be a better source of nutrition than a dog food claiming 22% crude protein derived from meat. Feeding quality sources of protein, particularly in working dogs, is essential. If a dog is expending high energy but fails to meet the dietary intake of nutrient protein, the body will metabolize functional protein required for normal cellular processes. As a result, anemia, increased susceptibility to disease, loss of body weight and eventually death can occur. If there is sufficient clinical evidence to suggest that high protein levels are essential for dogs with high energy output, there is equal evidence to suggest that high protein levels may be contraindicated in breeds which undergo rapid growth phases. Increase in nutritional skeletal diseases has closely paralleled the increase of high calorie, high protein diets in growing puppies. Besides producing a source of energy, protein intake directly effects growth rate. However, a direct relationship between high protein and bone disorders has not been clinically demonstrated. Rather, the correlation between high protein diets and skeletal diseases may lie in other related factors. For example, it has been clinically demonstrated that when puppies at risk for developing hip dysplasia were allowed to eat ad lib, they had a greater incidence of hip dysplasia than littermates who were placed on maintenance diets. Since protein content increases palatability, protein rich dog foods encourage an increase in food consumption. Therefore, puppies fed higher protein diets who are not limited in regard to the amount of food they consume are more prone to rapid growth phases and consequently skeletal disorders. Another concern regards protein levels in the relationship to kidney dysfunction in adult dogs. Because degraded protein products are excreted by the kidneys, erroneous conclusions were made which blamed excess dietary protein for kidney damage in adult dogs. There is no clinical evidence to suggest that high protein levels increase occurrence of kidney disorder in dogs. In fact, in one clinical trial, placing dogs diagnosed with kidney disease on high protein diets did not increase kidney damage or accelerate the disease process compared to those fed low level protein diets. Therefore, there is no medical evidence supporting protein-restricted diets in the treatment of dogs with kidney dysfunction. Furthermore, since protein is essential for repair of the body during and after illness, protein restriction may be contraindicated. FATS Dietary fatty acids are critical for growth, reproduction, and maintenance of healthy skin and coat. Additionally, fat plays a role in inflammation and immune regulation. A minimum of 5% fat in dry dog food is recommended, however, most commercial dog foods contain about 10% fat. Because working dogs may require up to twice as many calories as the average dog and because fat contains twice as many calories per weight as protein, fatty acid supplements are sometimes used to increase caloric intake without the need to increase amount of food intake. However, use of fat supplements beyond caloric needs can cause obesity, flatulence, and degeneration of red blood cells and the heart. Therefore, fat supplementation should be used under the direction of a veterinarian only. VITAMINS AND MINERALS Processing and storage of pet food usually leads to a reduction in essential vitamins and minerals. Therefore, most manufacturers of commercial dog foods address this issue by overcompensating the vitamin and mineral content prior to processing. Nowadays, most good quality dog foods contain a proper balance of vitamins and minerals and healthy dogs rarely require supplementation. Before this practice began, many pet owners adopted the practice of supplementing their dogs' diets. Because old practices die hard, some pet owners and breeders continue to supplement already-balanced diets. Interestingly, oversupplementation may contribute to increase in correlation between skeletal disorders and increased use of high protein, as previously discussed. Since most high-protein diets have complete vitamin and mineral nutrition, continued use of diet supplementation may be a primary contributor to skeletal disorders. The most common abuse of supplementation involves calcium and vitamin D. Owners and breeders of medium and large breeds continue to use calcium supplement probably as a prophylactic measure against eclampsia in pregnant bitches and skeletal problems in puppies. There is no medical evidence that calcium supplement prevents eclampsia in pregnant bitches. In fact, increased calcium intake prior to delivery for the purpose of increasing calcium production for lactation seems to have the exact opposite effect since it was found that excessive calcium intake prior to birth resulted in decrease in calcium once lactation began. It is hypothesized that supplementation interferes with normal homeostatic responses which allow the body to compensate for the calcium drain. In dogs and in growing puppies, maintaining the appropriate calcium:phosphorus ratio is essential for bone integrity. Imbalances in this ratio can lead to increased resorption or mineralization of bone resulting in skeletal abnormalities and disorders. To ensure that the appropriate calcium:phosphorus ratio is maintained, many owners and breeders insist upon supplementing nutritionally balanced dog food with calcium. Clinically, however, oversupplementation with calcium is associated with skeletal disorders such as osteochondritis. Additionally, increased calcium intake causes a disease process in dogs related to zinc deficiency, since excess calcium inhibits absorption of zinc. Furthermore, when calcium is supplemented with vitamin D, there is a greater risk for causing imbalance of the calcium:phosphorus ratio since vitamin D increases calcium absorption by the gastrointestinal tract. Therefore, administering calcium supplement, particularly with vitamin D, is a dangerous practice and is not recommended. * * * * * * * * * * * * * * * * * * * * * MESSAGE EXCEEDED PERMITTED LENGTH * * * * message truncated * * * * * * * * * * * * * * * * * * * * * * *
