Canine Nutrition

In an effort for the reader to make pragmatic use of this information, I have assimilated the technical research information and reduced it to a simplified form. This is probably far more information and detail than most folks want or need to know, however in order to create a program, a base line needed to be established and to do that required fairly precise detail. The first base line program I found was The UK National Research On Average Canine Nutrition Requirements Over The Life Of A Dog. While this provided a base to begin, it was not specific in terms of variances from puppy to senior requirements, which differ greatly.
Thus to provide more specific information the Board On Agriculture, National Research Council research on Nutrient Requirements of Dogs was utilized, published by The National Academy Press.

Balanced Diet
A balanced diet incorporates proteins, complex carbohydrates, beta carotenes, and amino and fatty acids in correct proportions. A balanced diet for a mature dog can be expressed in general terms as 25% protein, 50% complex carbohydrates, 25% beta carotenes.
Understanding the primary sources for each group, the benefits, and a comparison of the primary sources allows us to make decisions on specific balanced meals.

Proteins
Think of protein as energy. Digestible energy (DE) is the difference between the gross energy consumed and the gross energy in the feces. Metabolizable energy (ME) content of food is a valid expression of energy available to the dog and a basis for comparisons of the feeding value of foodstuffs. The ME requirements are in direct relationship the energy expended by the dog.
Protein makes up the enzymes that power chemical reactions and the hemoglobin that carries oxygen in the blood. Amino acids provide the raw material for all proteins. Because amino acids aren’t stored like fats and carbohydrates there is a daily requirement of amino acids to make new protein.

Essential Amino Acids
arginine
histidine
isoleucine
leucine
lysine Methionine
phenylalanine
threonine
tryptophan
valine

Factors of importance in determining the source and amount of protein to feed a dog are digestibility of the protein source, age, size, and daily energy expended in exercise. ME requirements generally increase in colder weather, yet weight generally reduces from summer months to winter months. Obesity in dogs is the ultimate result of caloric intake in excess of metabolic requirements.
Example of a primary source: Eight ounces of roasted chicken breast provides Rocco, our 75 pound Labrador with 25.59 grams of amino acids, exceeding the daily requirement of 16.69 grams.

Age and Protein
According to the BOA research, puppies require about two times as much energy per unit of body weight as adult dogs, however should be adjusted to 1.6 times when 40% of adult weight is achieved and 1.2 times when 80% of adult weight is achieved.
Senior dogs are then the opposite and energy requirements decrease in correlation with the age of the dog. Digestibility and calories should also be taken into consideration.

Fats: Polyunsaturated, Monounsaturated, Saturated and Trans Fats
There are good and there are bad fats, and there is good and there is bad cholesterol. Much has been researched relative to fat and cholesterol over the years in terms of human health, and fat and cholesterol affect dogs the same. They are on the one hand saved from the temptation of stopping off at the fast food restaurant, but are subjected to a variety of sources of saturated and trans fat in their diets by humans. Red meat is very high in crude fat, which stresses the dogs liver and is not digested easily, sometimes not at all. A diet of red meat can produce diarrhea and liver problems. When examined, the stool will actually show visible undigested fat globules spread throughout the specimen.

Good Fats
Poly and Monounsaturated fat both increase the good HDL cholesterol and decrease the bad LDL cholesterol.

Bad Fats
Saturated, mainly animal fats raise total blood cholesterol. Trans fats are produced by heating liquid oil in the presence of hydrogen (hydrogenation), worse for cholesterol levels than saturated fats (most manufactured dog foods).
The following chart is a comparison of typical primary protein sources in terms of fat, protein and calories. The data is based on one pound of baked protein (without bones). Choice comparable cuts were used for comparison (chuck roast, chicken breast, whitefish). Source: USDA Nutritional Data Base. The most digestible sources of protein are chicken and fish, also containing lowest saturated fat and calories.

Primary Protein Sources: One Pound
Source Calories Total. Fat Saturated Unsaturated Prot
Beef 1506 108g 43g 65g 124g
Chicken 748 16g 5g 11g 141g
Fish 581 13g 4g 9g 107g
Lamb 1347 93g 3g 90g 118g
Pork 1347 94g 35g 59g 117g

Carbohydrates: Sugars, Starches, Fibers
Complex carbohydrates provide energy and keeps the organs functioning properly. Carbohydrates are broken down during digestion in the intestine into their simplest form…sugar which enters the blood. Carbohydrates provide an economical source of energy in the diet of dogs. Cooked starch is well digested by adult dogs (Roseboom and Patton, 1929; Ivy et al., 1936; James and McCay, 1950; Heiman, 1959. Raw starch is less well utilized by dogs than is starch that has been subjected to some dextrinization by processing (for example, cooking, baking, or toasting) (Heiman, 1959).

Carbohydrate Source Comparisons
Typical primary carbohydrate sources are compared in the chart below. Amounts are equal to one cup of the ingredient and are analyzed cooked (boiled) (except bread). Source, USDA Nutritional Data Base
Carbohydrates Comparison: One Cup Cooked
Source Cal Prot Carb Fib Phos Pot Magne Selen
Rice 169 4 37 2 14mg 17mg 9mg 10mg
Pasta 145 5 27 1 81mg 89mg 23mg 22mg
Potato 134 3 31 3 62mg 512mg 31mg 0
Sweet Potato 344 5 80 6 89mg 604mg 33mg 2mg
Bread 233 7 44 3 89mg 96mg 23mg 27mg
Beans 225 15 40 11 251mg 713mg 80mg 2mg
Lentils 230 7 40 16 356mg 731mg 71mg 5mg


Minerals:
Calcium and Phosphorus
Calcium and phosphorus are considered together because of their close metabolic association. The ratio of dietary calcium and phosphorus may be as important for good nutrition but is of lesser significance than the absolute concentration of these minerals. A calcium: phosphorus ratio of 1.2:1 to 1.4:1 (by weight) in dog diets is generally considered optimal for maximum utilization. An optimal calcium: phosphorus ratio also minimizes the vitamin D requirement. The availability of calcium and phosphorus is a major factor affecting the dietary requirements of these elements (Schedle et al., 1968). Diets high in phytates or low in vitamin D adversely influence calcium absorption (Mellanby, 1920; Hoff-Jørgensen, 1946). However, vitamin D supplementation of diets low in calcium can cause pathological fractures, lameness, abnormal stance, and loss of skeletal density (Campbell, 1962).

Potassium
Dogs can be severely depleted of potassium in 30 days and repleted in 14 days (Abbrecht, 1972). An allowance for growth of 264 mg of potassium per kilogram of body weight per day is suggested as a minimum. It is estimated that the potassium requirements of normal dogs will be met by providing a concentration of 1.2 g potassium per 1,000 kcal dietary metabolizable energy.
Signs of deficiency are poor growth, restlessness, muscular paralysis, a tendency to dehydration, and lesions of the heart and kidney.

Sodium and Chlorine
The general practice is to include 1 percent sodium chloride in all dry dog diets, which provides approximately 95 mg sodium and 147 mg chlorine per kilogram of body weight per day. This amount is considered the appropriate allowance in that it meets the requirements and is not excessive for normal dogs, but the minimum requirement is greatly exceeded. Some natural feedstuffs may contain enough sodium and chlorine to meet minimum requirements, while various water supplies contain ample chlorine. Excess sodium thins the blood causing the heart to work harder.

Magnesium
Magnesium has been shown to be a dietary essential for the dog (Orent et al., 1932). However, the published experimental results regarding the quantitative dietary requirements for this mineral are inconsistent.

Iron
Iron is a part of the hemoglobin molecule and is essential for oxygen transport. Thus, iron-deficient dogs exhibit anemia and tissue anoxia. Both iron and copper are essential for preventing anemia.

Copper
Copper has been shown to be a dietary essential for prevention of anemia in dogs. Linton (1934) and Frost et al. (1939) reported that during copper deficiency iron was absorbed, but hemoglobin was not formed efficiently. Hemoglobin regeneration in anemic dogs (13 kg) did not occur unless 2 mg copper per day were given. This amount of copper also met the requirement for growth. The copper requirement for the majority of dog breeds appears to be quite low. It is estimated that a minimum of 0.8 mg copper per 1,000 kcal ME will meet the requirements of normal dogs, provided other dietary mineral concentrations are not excessive.

Manganese
There is essentially no published information regarding the manganese requirements for dogs, nor is there any description of the deficiency signs in this species. However, this mineral is known to have a role in catalyzing several metabolic reactions in other mammalian species. It is common practice to include manganese in diets for dogs. Ingredients used in natural ingredient dog diets may contribute adequate amounts of manganese to meet requirements, and it may not be necessary to add manganese to this type of diet. Based on the requirements of other animal species, it is estimated that the minimum manganese requirement for dogs is 1.4 mg/1,000 kcal ME.

Zinc
A concentration of 60 mg zinc per kilogram in dry natural-ingredient diets appears to meet the maintenance requirements for dogs provided calcium concentrations are not excessive. Excessive dietary calcium concentrations will decrease zinc availability, and various pathologically induced stresses will increase zinc requirements. Zinc requirements for dogs maintained on high-meat or purified diets may be slightly lower.

Iodine
Marine and Lenhart (1909) showed that dogs require small amounts of dietary iodine for the prevention of goiter. Belshaw et al. (1975). The proposed adequate dietary iodine concentration for normal dogs is 0.16 mg/1,000 kcal ME.

Selenium
The relationships between vitamin E and selenium requirements of many domestic animal species are well documented (NRC, 1983). The dietary selenium requirements of the dog, however, have not been studied in detail even though it has been reported (Fuller, 1971; Lannek and Lindberg, 1975; Van Vleet, 1980) that vitamin E or selenium administration may have a pharmacologic effect in treating a number of diseases of dogs. Based on these results, it would appear that a dietary concentration of 0.03 mg selenium per 1,000 kcal ME meets the requirements for dogs consuming a diet with adequate vitamin E levels. A diet containing up to 0.5 mg/kg selenium may be appropriate if vitamin E concentrations are limited.

Fluorine
A minimum requirement for fluorine has not been established for dogs. Experimental evidence shows that more mineral is not deposited in the bones of Beagles when a low-calcium, high-phosphorus diet is supplemented with fluorine (Krook, 1969; Henrikson et al., 1970; Krook et al., 1971).

Vitamins
Certain vitamins have been recognized as essential nutrients for dogs for more than 60 years. Despite this long history, precise quantitative requirements have not been established for every vitamin. Since several vitamins are rather unstable, and their destruction may be promoted by light, heat, oxidation, moisture, rancidity, or certain mineral elements, sufficient amounts should be provided to ensure that the recommended concentrations will be present when the diet is consumed. Just as important is the realization that markedly excessive intake of vitamins A and D may be harmful to dogs.

Vitamin A: Retinol
The earliest studies attempting to separate the functions of vitamins A and D on bone growth were carried out in dogs more than 60 years ago (see Mellanby, 1957). The actual dietary requirement for vitamin A in dogs was investigated by Frohring (1935; 1937). In studies, cod liver oil and carotene appeared to be equally well utilized as sources of vitamin A activity, even though cod liver oil is not an ideal test substance because it contains a variable amount of vitamin D that may interfere with vitamin A absorption if excessive. The data confirmed the earlier observation of Turner (1934) that dietary carotene (from carrots) may be converted to vitamin A and stored in the liver of dogs.
There has never been published a careful assessment of the daily vitamin A requirement for dogs based on the liver storage of the vitamin while feeding an acceptable form of vitamin A esters under controlled dietary circumstances. However, based on available information, the daily vitamin A requirement would be met by 75 IU per kilogram of body weight for adult maintenance and 202 IU per kilogram of body weight for growing puppies.

Vitamin D: Calciferol
The dog has been utilized extensively for studies of vitamin D metabolism, and it was in this species that the separate effects of vitamin A and vitamin D on bone growth and development were identified (see Mellanby, 1957). Since that initial discovery, the dog has been a widely used model in association with the influence of this vitamin on calcium and phosphorus metabolism. When the dietary calcium :phosphorus ratio is 1.2:1, daily vitamin D requirements should be met by 8 IU (0.20 µg) per kilogram of body weight for adult maintenance and 22 IU per kilogram of body weight.

Vitamin E: Tocopherol
While the need for vitamin E in dog diets was demonstrated by Anderson et al. (1939), the interrelationship with dietary selenium concentrations has only recently been studied (Van Vleet, 1975). Since selenium was identified as an essential nutrient in 1957 (Schwarz and Foltz, 1957), few of the vitamin E studies with dogs have taken this factor into account. Both nutrients are important in protecting cell membranes against peroxidation and the destructive effects of free radicals. Vitamin E serves to quench free radicals in the polyunsaturated fatty acids (PUFA) of membrane phospholipids; and selenium-containing glutathione peroxidase reduces peroxides, particularly those that form in the cytosol and in the mitochondrial matrix, thereby protecting the membrane PUFA from additional insult (Tappel, 1980).

Vitamin K: Phylloquinone
The metabolic need for vitamin K has been well established in the dog. Anderson and Barnhart (1964) have shown that vitamin K1 (2-methyl-3-phytyl-1,4-naphtho-quinone) stimulates prothrombin synthesis by the liver parenchymal cells in dogs made hypoprothrombinemic by coumarin compounds. Duello and Matschiner (1971a, isolated 19 vitamin K analogs in dog liver and suggested that most were absorbed from the intestine and were not tissue metabolites.

Thiamin: B1
The thiamin requirements of the normal adult dog for maintenance can be met by 20 µg per kilogram of body weight daily, and the growing dog by 40 µg per kilogram of body weight. All evidence suggests that 270 µg thiamin/1,000 kcal ME is adequate for maintenance and growth.

Riboflavin: B2
It is concluded that a daily intake of 50 µg riboflavin per kilogram of body weight for adult dogs and 100 µg riboflavin per kilogram of body weight for growing puppies will provide adequate levels of the vitamin for reasonable tissue storage. No data derived from dogs are available to give a dietary requirement for gestation and lactation. This translates to 0.68 mg riboflavin per 1,000 kcal of dietary ME.

Pantothenic Acid:
McKibben et al. (1939, 1940), Morgan and Simms (1940), and Fouts et al. (1940) demonstrated the necessity of pantothenic acid in the diet of the dog. Schaefer et al. (1942). These authors concluded that 100 µg calcium pantothenate per kilogram of body weight per day was adequate to prevent deficiency signs in growing puppies, but 60 µg per kilogram of body weight was insufficient. Adult dogs required less calcium pantothenate per unit of body weight than growing dogs.

Niacin
Historically the dog played an important role as a model for the study of pellagra in humans and in testing antipellagra vitamin preparations (Harvey et al., 1938). In a text on nutrition of humans, Chittenden (1907) described clinical signs of disturbances of the gastrointestinal tract with bloody discharge and inflammation of the mucous membrances of the mouth in a dog given a diet of bread and lard. Goldberger and Wheeler (1928) recognized the similarity between these signs of the disease known as "black tongue" in dogs and those of pellagra in humans (Goldberger and Wheeler, 1920). Elvehjem et al. (1937, 1938) demonstrated that nicotinic acid and nicotinamide were equally effective in curing black tongue and in preventing it in dogs given a black tongue-producing diet. Street and Cowgill (1937) also confirmed that nicotinic acid cured black tongue in dogs. The daily requirement of the adult dog will be met by 225 µg niacin per kilogram of body weight and for the growing dog by 450 µg per kilogram of body weight.

Vitamin B6: Pyridoxine
Vitamin B6, usually in the form of pyridoxal phosphate and occasionally as the amine, acts as a cofactor for a large number of enzymes involved in various aspects of amino acid metabolism. Values of 60 µg per kilogram per day for the growing dog and 22 µg per kilogram of body weight per day for the adult are suggested as the requirement.

Biotin
While a definitive requirement for biotin for the dog cannot be stated, the inclusion in a diet of 30 µg biotin per 1,000 kcal ME may be prudent as a safeguard against a possible deficiency.

Vitamin B12
In the absence of information on the requirement of dogs for vitamin B12, it is suggested that the recommended requirement for the baby pig (NRC, 1979) of 0.5 µg vitamin B12 per kilogram of body weight be adopted for maintenance of the adult dog and twice this level (1.0 µg per kilogram of body weight) be used for growth of puppies.

Vitamin C
Innes (1931) demonstrated that the dog, unlike the guinea pig, was independent of an exogenous supply of vitamin C. Puppies fed a diet devoid of vitamin C for 147 to 154 days showed neither growth impairment nor lesions of bones or teeth, although the same diet killed guinea pigs within 25 days with severe signs of scurvy. Furthermore, the livers of dogs on the deficient diet contained the vitamin in sufficient amounts to prevent the onset of scurvy in guinea pigs, indicating that the dog can synthesize its own vitamin C. Naismith (1958) showed that this synthetic ability is present in puppies during the first weeks of postnatal life. It is concluded that there is no adequate evidence to justify recommendation of routine vitamin C additions to the diet of the normal dog. However, dogs with hepatic dysfunction may have lowered plasma concentrations of ascorbic acid (Strombeck et al., 1983). Whether lower plasma concentrations are of clinical significance remains to be demonstrated.

Water
Water is undoubtedly the most important nutrient; it is vital to the functioning of all living cells. The body of the adult dog contains about 60 percent water (Gaebler and Choitz, 1964), and this proportion is even higher in the puppy. The body has a limited capacity to store water, and water deprivation causes death much more quickly than does deprivation of food. The individual dog's requirement for drinking water is self-regulated, depending on factors such as type of food, environmental temperature, amount of exercise, physiological state, and temperament. The need can be met by permitting free access to water at all times or by offering water at least 3 times a day. A dog should not be allowed large amounts of cold water immediately following violent exercise, because of the dangers of water intoxication. When the total ration consists of soft moist foods, which contain an intermediate amount of water, or of dry-type dog foods, water is a necessary adjunct to feeding.

Oils for the Coat and Skin
Good Guy...Bad Guy...Oils and your dog. There are good and bad oils. Both kinds compete for the same spot in the cell membranes. The good oils (safflower, sunflower, wheat germ, and flax, can displace other oil molecules in the cell membranes. Good oils bring down cholesterol and triglyceride levels in the body. Few dogs can tolerate flax seed oil, causing vomiting and or diarrhea. Oils, such as cottonseed, corn, palm and canola, also cannot be utilized by your dog. Many oils turn rancid fairly quickly once opened. Rancidity turns oils into trans-fatty acids, which can be dangerous to your dog's health. Manufacturers utilize a variety of preservation methods after rendering fat to oil, some not at all acceptable, and some natural, but fairly short lived. Most simply spray rendered chicken fat on the extruded product to make it more palatable to the dog
I started thinking that there was a reason we use 20/50 synthetic oil in the racing engines...it extended the engine life about ten times over non-synthetics. As convoluted as the analogy seems, that got me thinking about what kind of oil would be best for a dog. Berb's had been having some minor skin rashes and his coat was pretty dry and he shedded really badly. This is not good for a 159 pound long haired white monster. So I did an analysis of vegetable oils and took it to my vet. We drug out about ten DVM supplements off the shelf and found every one of them contained Safflower oil. Then we did comparisons of the oils and found out why.
1.Safflower oil is over 70% Lanoleic acid.
2.It is the lowest in saturated fat and highest in Polyunsaturated fat by a huge margin.
3. It yields the highest Vitamin E ATE of all other oils.
Because of the aforementioned, it is the most utilized by the system, most digestible, least allergenic, and provides a positive action in keeping the coat smooth and skin clear.