NUTRIENTS NUTRIENTSChoosing and feeding the best diet for your pet is such an easy thing to do, yet it is one area of health care often overlooked by both doctors and pet owners. Feeding the best diet is so important for total holistic health for your pet that most holistic doctors stress diet. By getting your pet on the best diet, some mild conditions (such as allergies) may respond without your needing to use other therapies. Even when other conventional or complementary therapies are indicated, feeding the most appropriate diet is the first rung on the ladder of holistic health care, often working synergistically with other supplements and therapies to providd the best health possible for your pet. Here are some important questions to keep in mind as you read this chapter.
How do you determine which diet is best for your pet?
Should you simply purchase the least expensive diet for your pet?
Should you purchase the well-known, heavily advertised, and promoted brands?
Should you trust your veterinarian to recommend the best diet for your pet?
Is a processed food best for your pet, or would a homemade diet be more suitable?
If you prepare a diet at home, should you cook the food, or is feeding it “raw” better for your pet?
In truth, it is up to you, the pet owner, to work with your veterinarian to help determine the most appropriate diet for your pet. This entire diet section is designed to give you the basic information you need to do just that.
Most pet owners, unfortunately, don’t really think a lot about what their pets eat. Sure, we all pay attention to ads touting one brand of food over another. Yet most pet owners (and some veterinarians) don’t know what’s really in the food they feed. Even though the answer is only a glance away, listed on the label required on each bag or can of food (assuming we can understand the label!), most of us never think to look.
Getting the proper diet is extremely important for pets. Because we are finally beginning to realize how important proper diet is for ourselves, many of us are trying to eat a more healthful diet. This may mean cutting back on calories, eating more fiber, or adding multivitamins and minerals to our diets. We know that certain diseases, including liver disease, heart disease, obesity, and cancers can be traced to improper diets, such as those too high in saturated fats or too low in fiber.
As owners make healthful dietary choices for themselves, it’s only natural they would do the same for their pets.
All food is not created equal. Turning to the ever-present pet food label we mentioned earlier, stop and take a look at the label on your pet’s food right now. Read the top three ingredients. Are they healthful ingredients such as whole dressed chicken (or another protein source), corn, and rice—or are they items such as chicken by-products, corn by-products, animal meal, blood meal, and the like? Exactly what are you feeding your pet? Is it possible that your choice of pet food may actually be hurting your pet? Is it possible that his food might be contributing to some of your pet’s health problems?
These questions must be answered so you can have the healthiest pet possible, but first you must understand the nutrients essential for your pet to determine how to feed your pet properly.
Whether you choose to prepare a diet at home or feed a natural, processed food, this part of the book will help you understand how to choose the best diet for your pet. For those of you who choose a processed food, feeding your pet the most natural, healthful diet possible is important. You will also learn how to do that in the Natural Health Bible for Dogs & Cats.
For readers who prefer, like many pet owners who seek the help of holistic veterinarians, to prepare a natural, balanced diet at home, the second half of this Diet section will help you do that as well.
Regardless of whether you feed a prepared diet or make one yourself, you’ll spend good money feeding your pet each and every day; therefore, it’s important that you know how to feed your pet most appropriately.
While it’s not common for veterinarians to see many obvious nutritional diseases in dogs and cats, there is no doubt that diet plays an important role in a pet’s health. As owners become more holistic in their approach to pet care, including their choice of diet, their pets will enjoy longer and healthier lives. Simply stated, an educated owner is the best pet owner.
Your pet needs many nutrients to not only sustain life but to encourage growth, promote a healthy coat, and allow proper function of his organs and immune system. An improperly nourished pet is unhealthy and prone to illness. Preventing illness with proper nutrition may be the most important part of a pet owner’s responsibility.
There are seven dietary classifications of nutrients—water, protein, carbohydrates, fats, vitamins, minerals, and food additives—each of which is important. Additives, though not technically nutrients, are found in many processed foods; therefore, it’s important to address them in this discussion. In formulating the best diet for pets, nutritionists take into account the percentage of each nutrient class the pet needs. It is extremely important for owners who choose to prepare homemade diets for their pets to carefully consider each class of nutrients. Dietary nutrient deficiencies are most likely to occur when owners prepare pets’ meals without following a tested recipe, or feed the least expensive, least healthful commercially prepared diets.
While most people don’t consider water a nutrient, it is without a doubt the most important one. An animal can survive after losing most of its fat or protein, but a 15% loss of body water results in death! Your pet’s body, just like your body, is made up mostly of water. The water content of the pet’s body varies with age; on average, water content of the pet’s body at birth is approximately 75 to 80%, while the percent of body water in an older pet might be more on the order of about 40%. The water content of plants can be anywhere from just above 0% (very dry plant matter such as aged hay), to about 11 to 16% for cereal grains, to about 99% for seaweed. Most people forget how important water is to a pet’s diet, yet water may be the most important nutrient. Too much or too little water can be fatal. For those interested in a holistic approach to feeding pets, you would be wise to consider using distilled water or pure spring water to reduce the possibility of contaminants.
While your pet’s food can supply a little or a lot of your pet’s daily water needs, water is usually supplied by always having available a fresh bowl of clean water.
There is some debate concerning whether tap water is adequate, or whether bottled or distilled water is preferable. No published studies prove one type of water is better than another, or that any type of water causes disease in pets. Many holistic pet owners prefer bottled or filtered water to tap water. A recent report in a popular periodical tested a number of brands of bottled water and found them no different from plain tap water. City tap water is chlorinated. While this causes concern to some owners, chlorination also kills various bacteria that could cause food poisoning in pets if the bacteria were present in high numbers. Using non-chlorinated water could predispose the pet to poisoning by these bacteria (as well as any protozoal organisms) if they are present in the water source. Cities will usually provide a chemical analysis of the water supply if requested by owners. The decision about which water source to use is a personal one; most clients offer their pets whichever type of water they themselves drink.
Body water serves several useful functions. First, water is used for body heat regulation. Water in the body transfers heat produced during metabolism by the cells to the outside surface of the body. The heat is released through sweating (although our pets can’t do this) and through evaporation in the lungs. Second, water is used for transportation of body nutrients, from the food the pet eats into the cells where the nutrients are used for cellular processes such as energy production, cellular metabolism, and making hormones. Third, water allows the body to transport waste material from the cells to the outside of the body (in the form of urine and fecal production). Finally, water assists in lubricating the various body surfaces (joints, intestines, and organs of the abdomen and chest).
Dry food is 6 to 10% water, soft-moist is 23 to 40% water, and canned food is 68 to 78% water. As a rule, the amount of water consumed by mature dogs and cats maintained at a comfortable environmental temperature is about 2.5 times the amount of dry matter consumed in food.
Dry food is the least expensive per pound. Soft-moist food often contains a high sugar or propylene glycol content. Excess sugar may contribute to diabetes in dogs and cats, and propylene glycol can cause anemia in cats. Soft-moist (semi-moist) foods are best avoided by owners desiring a more holistic diet. Canned food contains a lot of water; therefore, a dog or cat consuming a lot of canned food (or homemade diet) will drink less water. For owners choosing to feed a wholesome, natural processed diets, offering dry food (supplemented with canned food as desired) seems a popular option. Dry food is not quite as messy as canned food, costs less, is less likely to spoil quickly, and promotes healthy gums and teeth. Periodontal tartar seems to build up more slowly when pets eat a diet of dry food, although pets who chew a lot (pets fed bones) also build up tartar less quickly. Tartar buildup and periodontal disease occur differently in every pet, usually as a result of diet plus individual susceptibility to this common infectious disease of dogs and cats.
Water should be increased in times of illness, when fever is present, when the environmental temperature increases, if your pet pants excessively, or when your pet is taking certain medications (such as corticosteroids or diuretics) that result in an increased urinary output.
Carbohydrates—sugars, starches, and fiber—are excellent sources of energy in pet foods. The body of a pet actually contains only small amounts of unused carbohydrates; carbohydrates in the diet that the pet does not need are stored as glycogen and body fat. Plants, however, contain a large amount of carbohydrates and are included in the diets of pets to provide energy or fiber.
Natural sugars and starches found in plants are useful for supplying energy and are easily digested by the pet (see below). You should avoid feeding your pet excess sugars, especially man-made sugars that often added to increase the flavoring of the food. Sugars compete with essential dietary nutrients for digestion and absorption, can contribute to obesity, and may predispose pets to diabetes.
Also avoid excess quantities of poorly digestible carbohydrates (wheat, oats, soybeans) in your pet’s diet as they contribute to excess intestinal gas (flatus). Excess fermentation of poorly digestible carbohydrates may contribute to bloat in dogs.
Once digested and absorbed by the pet, one of three things can happen to the sugars and starches: They are immediately used for energy, they are stored as glycogen in the liver (to be used at a future time for energy), or they can be stored as fat. Fiber, however, is not digested by the pet. Fiber serves as the structural part of the plant; common plant fibers include cellulose and lignin. Including fiber in the diet is important for normal intestinal function. Excess dietary fiber is often used when formulating diets for overweight pets, for pets with certain intestinal problems, and for pets with diabetes to help them control their absorption of sugars and starches from the diet.
Fiber is sometimes added to the diet to prevent both diarrhea and constipation. Fiber also helps the animal feel full so he doesn’t overfeed and become obese. Cheaper pet foods often have too much fiber as a filler. As a result, pets can become full before consuming the needed nutrients and can exhibit nutritional deficiencies.
While both dogs and cats can digest and absorb carbohydrates, neither has specific dietary requirements for this nutrient form. Cats especially, being true carnivores, do not need carbohydrates in their diets. Cats are able to easily maintain blood glucose levels when fed high-protein, low-carbohydrate diets. The sugar transporting system of the cat’s intestinal system does not adapt to varying levels of dietary carbohydrates as cats have low activities of intestinal disacchardiase (sucrase and lactase) enzymes. Cats also only produce about 5% of the pancreatic amylase enzyme (the carbohydrate-digesting enzyme) that dogs produce. Also, unlike dogs, cats do not possess the liver enzyme activity (hepatic glucokinase), which limits their ability to metabolize large amounts of carbohydrates. Many commercial cat foods contain large amounts of carbohydrates (especially corn), which lower the price of the food. (Corn, a grain which supplies carbohydrates and protein, is less expensive than animal meats as a protein source.) These foods should not be fed to cats, who require large amounts of animal protein and minimal amounts of dietary carbohydrates.
Protein is composed of amino acids, which are the building blocks of the body. Proteins are used for energy and in the production of enzymes, hormones, antibodies, and in making muscle and other structural tissues. While people often mistakenly are concerned about the protein content of food, in reality it’s the amino acids that are important. The protein sources used in formulating the diet must contain the proper amounts of the essential amino acids needed, or your pet will suffer from an amino acid deficiency despite an adequate protein intake.
While plants can produce all of the 24 amino acids, they can’t really produce enough of each or in the right amounts. With few exceptions, an all-plant (vegetarian) diet would not provide enough of the right amounts and right balance of amino acids required for our pets. Keep in mind that cats are true carnivores requiring meat in their diets; and even though dogs are more omnivorous than cats, they too are carnivores and must have meat in their diet.
Pets cannot make all the amino acids they need; therefore, their diets must provide those they cannot make in their bodies. These required amino acids are called essential amino acids. Nonessential amino acids, on the other hand, can be made by the pet’s body from other amino acids that they get through their diet. A high-quality protein diet contains all the essential amino acids required in the right amounts and right ratios. Protein is supplied in a pet’s diet through animal (preferably) or plant material; in cheaper diets the animal source might be “animal meal” or “animal by-products” rather than whole, dressed animal. These less wholesome ingredients are not desired in the diets of pets.
| AMINO ACIDS | |
| Essential | Nonessential |
| Arginine | Alanine |
| Citrulline (conditionally in cats) | Asparagine |
| Histidine | Aspartate |
| Isoleucine | Cysteine |
| Leucine | Glutamate |
| Lysine | Glutamine |
| Methionine | Glycine |
| Phenylalanine | Proline |
| Taurine | (essential in cats) Serine |
| Threonine | Tyrosine |
| Tryptophan | Valine |
The biological value of protein is based on the protein’s unique combination of its building blocks, the amino acids. People and animals use the amino acids obtained by digestion of protein for growth and building tissues and organs. When discussing proteins, the biological value of the protein is important. Eggs are ranked at 100, being considered the best food for providing high-quality protein. Digestibility is also important; the protein must be easily digested and assimilated into the body before it can be of any value to the pet. While it would be most helpful to know the amino acid content of the protein in the commercial pet foods, the label only needs to list the crude protein. It’s important to read the label to see the quality of ingredients, as crude protein can include items such as feather meal, hair, hooves, tendons, and ligaments. While these animal by-products certainly provide protein, they are essentially non-digestible and provide no biologic value (amino acids) to the pet. Cheaper, generic foods are more likely to contain these byproducts as sources of protein for the diet.
Protein deficiency is not common but can occur during illness, when the animal eats less or refuses to eat. In this situation, the pet still requires amino acids. If he isn’t eating, the pet will literally break down his own muscle tissue to supply his body with protein. This happens quite readily when the pet becomes ill, and is an important reason why sick pets don’t recover from illness quickly. Providing food for a sick pet is so essential that hospitalized pets are force-fed to maintain a positive energy and protein balance to help them recover quickly. You can see how important it is to make sure that sick pets continue to eat!
There are some unique requirements for amino acids in our pets. For example, cats, being true carnivores, require high levels of the amino acid taurine. Taurine is only found in meat; cats cannot be fed diets based on soy, dairy, or plant material without added taurine. Taurine deficiency has been associated with blindness and dilated cardiomyopathy in cats.
Taurine is not made into proteins synthesized by the body but instead remains as a free amino acid. It exists as a free amino acid in many body tissues, including the brain, nervous tissue, heart muscle, skeletal muscle, retina of the eye, liver, red and white blood cells, as well as in milk and as a complex with bile salts excreted by the gallbladder.
Since taurine is a free amino acid found in meat, it is important when preparing diets at home that if the meat is cooked in water, the water be added back to the diet to preserve taurine. That’s because the longer the meat is cooked, the more taurine will leach into the water. Owners choosing to feed raw meat to their cats will not have this problem.
Cats also require citrulline as they cannot synthesize it. They can convert arginine to citrulline as long as the diet contains adequate amounts of arginine. Diets deficient in arginine, citrulline, and the amino acid ornithine predispose the cat to developing hyperammonemia (too much ammonia in the blood), which can be fatal. Since most protein sources contain adequate arginine, additional supplementation is usually not needed. Cats with hepatic lipidosis are often supplemented with arginine to help detoxify ammonia and prevent worsening of clinical signs. Diets designed for pets with cancer contain additional arginine as this amino acid decreases tumor growth and spreading (metastasis). Arginine is also involved in the formation of nitric acid. Nitric acid is used by the body to help regulate blood flow through blood vessels and regulate blood pressure. Nitrates (isosorbide dinitrate, nitroglycerin) may be used by doctors to help pets with heart disease. It may be possible that additional arginine could be helpful in controlling blood flow and blood pressure in dogs and cats with heart disease, but this has not been investigated.
Excess glutamic acid can be detrimental to cats and cause vomiting and thiamin deficiency. Glutamic acid is found in plant proteins and is relatively low in animal proteins. Diets with high levels of vegetable matter may contain excess glutamic acid.
Glutamine is present in high-quality proteins and is not often added to pet foods. Additionally, because L-glutamine is destroyed by heating and cooking, supplementation with L-glutamine is best accomplished by adding the supplement (often in a powdered or capsule form) to the food immediately before feeding. (Capsule glutamine supplements can be given directly to the pet as directed by the veterinarian.) Dogs and cats experiencing stress—illness, cancer chemotherapy, immunosuppressive illnesses (such as feline leukemia virus or feline immunodeficiency virus infection), or surgery—may not be able to maintain glutamine stores in their bodies and might benefit from additional supplementation. Glutamine may also retard the cachexia (wasting) seen in many pets with cancer. Glutamine, being the preferred energy source for cells of the intestinal tract, is useful as a supplement for pets with acute and chronic gastroenteritis (especially when diarrhea occurs) and from gastroenteritis that results from cancer chemotherapy.
Excess dietary protein has been linked to fear-related territorial aggression in some dogs. It is theorized that increased protein interferes with the transport of the amino acid tryptophan across the blood-brain barrier, which can decrease serotonin formation. Serotonin is an important neurotransmitter, and low levels have been linked to various behavioral problems. Often feeding these dogs a reduced-protein diet can cure this behavioral disorder.
Fats are used for energy and are necessary for the absorption of vitamins A, D, E, and K. Fats also are used in the body’s production of hormones, for insulation, for protection of vital organs, for lubrication, for buoyancy, and as precursors to amino acids. Fats also make diets more palatable (diets high in fats taste good!). Excess concentrations of fats can lead to obesity, hepatic lipidosis (fatty liver disease), and pancreatitis. Cholesterol is a common animal fat. While excess cholesterol can cause problems in both people and pets, every person and animal needs some cholesterol. Cholesterol is important because important hormones (testosterone, progesterone, estrogen) are made from cholesterol.
Fats are either saturated or unsaturated, which refers to the chemical structure. Excessive amounts of saturated fats are linked to arteriosclerosis in people and may be unhealthy in pets as well. While both plants and animals contain higher amounts of saturated fats than unsaturated fats, animal tissue contains higher amounts of saturated fats than plant tissue. Hydrogenated oils, made chemically by adding hydrogen to vegetable oils, are also harmful to people and pets and interfere with the production of protective prostaglandins.
Fat deficiency, or rather fatty acid deficiency, is rare in pets; it is most likely to occur in pets fed cheaper generic diets, and in pets with maldigestion and malabsorption intestinal conditions. Certain fatty acids (omega-3 fatty acids) can be supplemented by your doctor to help with various skin problems—specifically atopic dermatitis, a form of allergic dermatitis. Fatty acids are being investigated in both people and pets to help control a variety of ailments, including heart disease, arthritis, and kidney disease.
Owners often attempt to supplement fats in a pet’s diets by adding a few spoonfuls of vegetable oil to the diet. While this may not be harmful, it is usually not necessary and will not provide essential fatty acids necessary for improved health or disease treatment. Fatty acid supplementation may be indicated for pets with a variety of medical disorders, and can be beneficial for all pets by increasing the dietary ratio of omega-3 to omega-6 fatty acids.
Omega-3 fatty acids—eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)—are derived from fish oils of coldwater fish (salmon, trout, or most commonly menhaden fish) and flax-seed. Omega-6 fatty acids—linoleic acid (LA) and gamma-linolenic acid (GLA)—are derived from the oils of seeds such as evening primrose, black currant, and borage. Omega-9 fatty acids have no known use in treating our pets.
In general, the products of omega-3 (specifically EPA) and one omega-6 fatty acid (DGLA) are less inflammatory than are the products of arachidonic acid (another omega-6 fatty acid). Supplementation of the diet with omega-3 fatty acids (generally considered anti-inflammatory fatty acids) is useful to decrease inflammation in the body. Since metabolism of the omega-6 fatty acids tend to cause inflammation, supplying a large amount of omega-3 fatty acids favors the production of non-inflammatory chemicals.
Note: Flaxseed oil is a popular source of alpha-linoleic acid (ALA), an omega-3 fatty acid that is ultimately converted to EPA and DHA. However, many species of pets (probably including dogs and cats) and some people cannot convert ALA to these other more active non-inflammatory omega-3 fatty acids. In one study in people, flaxseed oil was ineffective in reducing symptoms or raising levels of EPA and DHA. While flaxseed oil has been suggested as a less smelly substitute for fish oil, no evidence supports it as effective when used for the same therapeutic purposes as fish oil. Therefore, supplementation with EPA and DHA is important, and this is the reason flaxseed oil is not recommended as the sole fatty acid supplement for pets. Flaxseed oil can, however, be used to provide ALA and as a coat conditioner.
Minerals include such substances as calcium, phosphorus, iron, and zinc, among others. As a rule, minerals function as coenzymes that help control numerous biochemical reactions in the body. Minerals also are constituents of bone and muscle, and are involved in the growth and regeneration of tissues. Mineral deficiencies rarely occur in pets. In dogs fed cheap generic diets, zinc deficiency commonly occurs, causing crusting skin lesions, often prominent around the mouth and nose.
Mineral excess can occur by overzealous administration of minerals by owners, specifically calcium and phosphorus. This may be especially problematic in dogs. Many owners give their growing puppies calcium pills, thinking this will help with skeletal growth. Too much calcium can actually cause problems, including hip dysplasia. Excessive iron given to dogs and cats (which can happen if human vitamin products containing iron are given to the pet) can be fatal.
Note: An excess of minerals can occur easily in pets. Mineral supplementation is not recommended unless directed by your veterinarian.
Minerals commonly found in plants include calcium, phosphorus, and magnesium. (These are also found in bone, and are provided in our pets’ diets through the addition of bonemeal or similar supplements.) Minerals commonly found in animals (in muscle tissue) include potassium, sodium, and chlorine. See Part Two for a more thorough discussion of minerals.
Like minerals, vitamins function as enzymes or coenzymes. Pure vitamin deficiencies or toxicities are rarely encountered in pets fed quality processed diets, as pet food manufacturers over-compensate and make sure the food contains more than enough of these compounds. There are a few rare exceptions: vitamin K deficiency that can occur rarely as a result of chronic diarrhea, acute poisoning by warfarin-type rat poisons, poor-quality diets that contain an insufficient amount of fat, and antibiotic therapies (antibiotics can kill the intestinal bacteria which manufacture vitamin K). Also, large amounts of ingested raw egg whites can result in a biotin deficiency, though this is also rare.
Vitamin toxicities can occur if owners supplement their pets’ diets with excessive amounts of human or animal vitamin preparations. See Part Two for a more thorough discussion of vitamins.
Additives can include a number of substances, such as chemical preservatives, artificial coloring, and artificial flavors.
Preservatives are essential in preventing spoilage of food. As people learned more about food and as chemicals were developed to prevent spoilage, the incidence of food poisoning drastically decreased. However, chemicals also have a bad side. Long-term ingestion of certain chemicals might be harmful and may be linked to chronic diseases including cancers. Purists try to avoid manmade chemicals in diets fed to pets. However, it is important that owners not totally abandon preservatives or they risk causing illness in pets due to food poisoning. Some manufacturers of pet foods have responded to the preference to move away from chemicals and include more natural preservatives. When choosing commercially prepared diets, antioxidants such as vitamin E and vitamin C have replaced chemicals such as ethoxyquin, BHA, and BHT (to follow). Careful reading of the label will inform owners what chemicals, if any, are added to the pet’s food. For pet owners who choose to prepare diets at home, it is almost impossible to formulate diets that are resistant to spoiling. Therefore, owners should refrigerate or freeze small amounts of prepared food when making a homemade diet. The food can be defrosted and fed to the pet as needed.
Artificial colors and flavors are really not necessary in pet foods. Because dogs and cats don’t have the color vision of people, they don’t care about the color of the food you choose. Colors are added to be more attractive to owners who must make purchase decisions regarding the large number of foods available to them. Artificial flavors should not be needed if the food is palatable. Whenever artificial flavors are added to foods, owners should question whether the pet would eat the food without the flavors. If the pet wouldn’t, one has to wonder why the owner would choose to purchase that food!
For a more thorough discussion of the chemicals commonly included in commercial pet foods.
While not a nutrient in the true sense of the word, the energy content of a food is important, as food must provide energy not only for survival of the pet, but also for processes including normal metabolism, healing, reproduction, lactation for nursing animals, growth, and everyday activity. For simplicity sake, energy is provided in food by fats, carbohydrates, and proteins. The energy content of food is defined in kilocalories, which is 1,000 calories (in nutrition language, the word calorie usually means kilocalorie). If the food is a premium food and correctly balanced, as a rule, feeding the amount needed to meet the pet’s energy requirement provides the proper amount of all needed nutrients. The amount to feed can be calculated by dividing the animal’s energy requirement by the energy density of the food. In practice, most owners don’t wish to do this. Pet food companies have already done this and offer suggested feeding amounts that vary with pet weights on the food package.