TOPIC IN NUTRITION Part 3

CARBOHYDRATES

Carbohydrate is the term for a family of nutrients consisting of sugars, starches, gum and cellulose (fiber). These nutrients range from simple sugars (glucose, fructose and lactose) to complex carbohydrates (starches and cellulose in grains, vegetables, fruits). Carbohydrates are derived from plant life….vegetables, fruits and grains. Commercial dog foods all contain carbohydrates. Corn, wheat, soy, rice, barley, alfalfa, quinoa, oats, millet….these are examples of grains commonly used in pet foods. Potato, sweet potato, peas, and tapioca are examples of other carbohydrate ingredients often found in pet food.

During digestion, complex carbohydrates are broken down by digestive enzymes into simple sugars such as glucose. Once in a simple form, the sugar is absorbed rapidly into the bloodstream. Glucose is necessary in the body for energy and brain function. The liver can synthesize glucose from amino acids (derived from protein) and glycerol (derived from fatty acids).

You won’t find carbohydrates listed on the “guaranteed analysis” of any commercial dog foods, because there is no absolute need for carbohydrates in the dog’s diet. Dogs do, however, produce the digestive enzymes to be able to digest carbohydrates, so small to moderate amounts are not harmful.  Large amounts of carbohydrates stimulate the dog to consume excess calories in an effort to obtain sufficient nutrients, thereby promoting obesity.

While carbohydrates are generally not necessary in a dog’s diet, they can be useful in certain situations, such as liver or renal issues where nitrogen and phosphorus levels need to be regulated. Carbohydrates are needed for the lactating dam, who must have plenty of blood glucose for production of milk. Puppies need some carbohydrates as they are being weaned from their mother’s milk, which is high in sugar. High-performance and working dogs may benefit from some extra calories provided by carbohydrates. Grains and starches can be included in the diet, but should make up not more than about 25% of the meal. The amount of carbohydrates contained in kibbled foods is typically between 50-80%-far more than is optimal.

Grain-free foods are becoming popular. But the ingredients that replace grains in these formulas are still starchy carbohydrates; the one most commonly used is potato. Sweet potatoes, peas and tapioca are other high-carbohydrate ingredients used to replace grains in pet foods.

Potatoes belong to the nightshade family, along with tomatoes, peppers, tobacco and eggplant. Many doctors have traditionally advised patients with arthritis to avoid nightshade vegetables. These foods are high in solanine alkaloids, chemical substances with strong toxic effects….and the greener the vegetable, the more alkaloids it contains. Green potatoes and fried green tomatoes are definitely out! Sweet potatoes, however, are not nightshade vegetables; they are in the morning glory family.

Most plant-based foods also contain cellulose or fiber, a type of carbohydrate which dogs cannot digest.  Dogs do not produce the digestive enzyme “cellulase” which is needed to break down fibrous plant cell walls. Fiber is generally a low-cost ”filler” ingredient. Manufacturers also include fiber is to prevent kibble pieces from crumbling apart, and to extend product shelf life.

Avoid commercial foods that include beet pulp, peanut hulls, brans and other fibrous, non-nutritious fillers. If your dog eats raw meaty bones he will be getting plenty of bulk in his diet. If your dog does not eat raw bones, you can include some processed fruits and/or vegetables in the diet for a source of fiber.

Carbohydrates should be avoided by dogs with diabetes, seizures, and hypothyroidism. Because dogs have the anatomy of a carnivore, carbohydrates are difficult for them to digest; they make stools large, and produce gas. Grains and starches should also be avoided by dogs with arthritis, allergies and other inflammatory conditions. Shop for a food with a good primary animal based protein, and minimal carbohydrates.

AFLATOXINS

Penicillin is a mycotoxin; a poison produced by a mold. Penicillin destroys bacterial cell walls, thereby killing bacteria. Man has harnessed penicillin to use to our benefit to help fight infections. Most mycotoxins, however, are not beneficial; and in fact can kill.

One of the most potent naturally-occurring poisons is aflatoxin. Iraqi officials admitted in 1995 to producing aflatoxin to be used as a biological weapon. Aflatoxin is produced by the fungus “Aspergillus”. Foods rich in carbohydrates such as corn, rice and wheat support the growth of this fungus; particularly grains deemed not suitable for human consumption, that have may have been stored in a warehouse for weeks or even months.

Aspergillus growth is microscopic, so you can’t see it with the naked eye....and the toxins produced are odorless, so you can’t detect them by smell, either. Aflatoxin ingestion in large enough amounts causes death by liver failure. If ingested at low levels over time, aflatoxins are known to cause liver cancer in humans. In livestock, other effects are decreased growth rate, lowered milk or egg production, and immunosuppression.

 Kibble, due to its high carbohydrate content, is a perfect medium for growing aspergillus fungus. Once a bag of kibble is opened and exposed to air, it is more than likely exposed to fungal spores which are omnipresent in the air. If the food becomes damp it will readily support fungal growth. If you buy kibble, try to buy your food in small batches; check expiration dates carefully; and, once the bag is opened, switch the food to an airtight container. You might even consider keeping your kibble in the refrigerator or freezer once the bag is opened. This will help maintain freshness.

Remember the huge Menu food recall? Their foods were contaminated with aflatoxin from the corn they used…..BEFORE it was processed into dog food. There were many deaths associated with that incident. Peanuts and deadfall nuts are also commonly contaminated with aflatoxins. Aflatoxin poisoning is a worldwide problem, because fungal spores are ubiquitous.

 There are thousands of other mycotoxins that can be included in carbohydrate-based foods, including vomitoxins, fumonisins, and patulins. These have also sickened and killed pets, prompting recalls. The cooking process destroys the molds and fungi, but not the toxins that they produce. Mycotoxicosis has been a major problem for dogs ever since man first invented dry dog foods.

STORAGE MITES

Dry dog foods are primarily composed of low-cost, low-priority grains with long set times…ideal breeding grounds for mold and mites. Have you heard of “storage mites”? Storage mites are cousins of the dust mites, a common allergen. Storage mites feed and reproduce in the flours that are processed into pet food. When the flours are processed into dog food, these storage mite carcasses are then in the dog food.

In a study published in the American Journal of Veterinary Research (Jan 2003), 94% of dogs with allergic dermatitis had antibodies against storage mites. The study concludes, “Storage mite sensitivity in dogs may be as important, if not more important, than dust mite sensitivity.” Another study repeated these findings.

Storage mites in kibble are likely a significant source of allergies in our dogs. If your dog is fed kibble containing grains and suffers from allergies, storage mites could be the problem. Consider switching to a grain-free diet. (And yes, rice is a grain!)

FRUITS and VEGETABLES

Many of our dogs love fruits and vegetables. If your fresh diet does not include bones, you will need to add some fruits and vegetables for their fiber content. Small amounts are not harmful and may even provide some significant nutritional benefits. Fruits and vegetables must be cooked or pureed for the dog to be able to derive any nutritional benefit from them.

 Berries such as red raspberry, blueberry, cherry and cranberry are often included in high-end commercial diets. These berries contain phytonutrients such as ellagitanins, anthocyanins, salicylic acid, quercitin and catechins. These nutrients have proven beneficial in reducing cancer risk, enchancing circulation, improving memory, enhancing immunity, preventing cancer, fighting infection, and easing inflammation and pain from arthritis. It will be interesting to watch further research in this area!!

Cranberry reduces the risk of struvite bladder stones, the stones that commonly form as a result of urinary tract infection. However, cranberry can actually increase the risk of oxalate stones in dogs who are genetically predisposed to their formation. The reason for this is the oxalic acid contained in cranberries. Oxalic acid is a food ingredient that binds with calcium to form the compound calcium oxalate. Foods that contain oxalic acid should be limited in the diet so as not to create a calcium deficiency or promote bladder and kidney stones in dogs who are prone to them.

High amounts of oxalate are also contained in barley, corn, wheat, oats, beets, soy, figs, Brussels sprouts, broccoli, parsley, spinach, swiss chard, green and wax beans, blackberries, blueberries, carrots, celery, dandelion greens, grapefruit, kiwi, endive, gooseberries, okra, oranges, black raspberries, strawberries and sweet potatoes. Higher amounts of calcium may be needed if the diet contains significant amounts of high oxalate containing foods.

Fruits and vegetables should be pureed or steamed. If eaten raw, they can’t be digested, and your dog won’t be able to use the nutrients they contain.

Cruciferous vegetables can suppress thyroid function if large amounts are fed raw. This includes broccoli, cauliflower, brussels sprouts, bok choy, cabbage, kale, collard greens, mustard greens, turnips, turnip greens, watercress, rutabaga, daikon, and kohlrabi.  Fortunately, the thyroid-inhibiting substances in these foods are inactivated by cooking, or light steaming, so your dog can still enjoy the valuable antioxidant and cancer- protective effects of these cruciferous vegetables

Canned Pumpkin, fed in small amounts, is often recommended for digestion, to help both diarrhea and constipation.

PROBIOTICS

“Pro Bios” means literally “for life”. The term “probiotics” refers to the life-supporting beneficial microorganisms in the digestive tract. There are several types of probiotic organisms, mostly bacteria of the genus lactobacillus or bifidobacteria — often called acidophilus and bifidus. These bacteria help to keep the unfriendly, pathogenic bacteria in check.  Probiotic bacteria also manufacture vitamins B6, B12, K, and folic acid. When the numbers of these probiotics in the intestines are reduced through taking antibiotics, stress, or illness, an overgrowth of “bad” microorganisms can result. Without the probiotics to keep the pathogens under control, the dog may develop digestive upsets, diarrhea or yeast infections.

  Supplementing the diet with probiotics can help replace and maintain the levels of friendly bacteria in the digestive tract. They can also help with firmer stools. A probiotic supplement is useful after antibiotic therapy, after a parvo virus infection, and during other times of stress (boarding, traveling, competition, training or after surgery). Probiotics are a useful first-line treatment for puppies with diarrhea and are great to add to the diet of the new mother. Probiotics can help reduce the risk of infection and allergies.

 High heat involved in manufacturing canned and kibbled foods destroys probiotic bacteria, so it is a good idea to add any probiotics to food just prior to mealtime. Yogurt and kefir with active cultures are great natural sources of probiotics. Commercial supplements are also available such as Bene-Bac and FasTrac. Probiotics are sensitive to heat. They are stable at room temperature, but will have a longer shelf life if kept refrigerated.

The highly acid environment of the dog’s stomach kills most bacteria. This explains how dogs can eat raw food or foods loaded with bacteria and not become sick. One common concern about probiotics is survivability past the stomach. Lactobacillus acidophilus bacteria, however, are specially adapted to survive and thrive in an acid environment. The word “acidophilus" literally means “acid-lover”! Lactobacilli love acid so much that they make their own…they secrete plenty of acid to maintain their preferred low-pH environment. In newborn animals, the lactic acid produced by these lactobacilli help with digestion until the babies are able to make enough of their own stomach acids. This is one good reason to include yogurt with active cultures in your homemade puppy formula.

Other probiotic microorganisms prefer the less acidic environment of the intestines, and will successfully pass through the stomach and continue on to the colon. There are always some probiotic microorganisms that cannot survive the extreme acid conditions in the dog’s stomach, and that is why the suggested dosage amounts of probiotics are high.

PREBIOTICS

The term “prebiotic” refers to fibrous substances in the diet which ferment, feed and support the growth of “probiotic” bacteria. Beet pulp and inulin are examples. Prebiotics are extremely helpful for horses, cows and other herbivores. Dogs are not designed to eat fibrous foods, nor do they have the capability to ferment food. They don’t have multi-chambered stomachs, and they don’t ruminate their food. Dogs are carnivores, and have a short and simple digestive tract. Prebiotics are unnecessary in the canine diet, and can cause gas, bloat, large stools and digestive upset.

GLUCOSAMINE

One of the hottest topics in nutrition is glucosaminoglycans or GAGs. The mucoid proteins glucosamine, chondroitin and hyaluronate are examples of GAGs. These GAGs promote the rebuilding of collagen, cartilage and joint structures.

Dogs can obtain glucosamine in their diet by eating gristle found in meat. The commercial supplement Glyco-Flex is derived from green-lipped mussel, which is a rich source of GAGs.  Glyco-Flex is used to help relieve the pain and swelling associated with arthritis.

Theriogenologists (veterinarians specializing in reproduction) often recommend supplementing studs with Glyco-Flex to improve sperm count, quality and motility. Some commercial dog foods (such as ZiwiPeak and Blue Buffalo) also include green-lipped mussel in their formulas.

Glucosamine supplements are not recommended during pregnancy, based on a study in rats which linked glucosamine intake during pregnancy to birth defects. More studies hopefully will be done in this area.

SELENIUM

 Selenium is a vital trace mineral which plants obtain from the soil, and animals obtain from these plants. Selenium is needed to produce antioxidant enzymes, and to help metabolize fats. Other selenoproteins help regulate thyroid function and play a role in the immune system. Selenium deficiency is rare in the U.S. but is seen in other countries, most notably China and Russia, where soil concentration of selenium is low.

According to the National Institute for Health, there is evidence that selenium deficiency may contribute to development of heart disease, hypothyroidism, and a weakened immune system.

 Three specific diseases have been associated with selenium deficiency:

  Keshan Disease, which results in an enlarged heart and poor heart function, occurs in selenium deficient children.

  Kashin-Beck Disease, which results in osteoarthropathy

  Myxedematous Endemic Cretinism, which results in mental retardation

Selenium deficiency can cause cartilage degeneration and may play a role in hip dysplasia, heart disease and cancer. Too much selenium, however, also can cause illness.

 Selenium in the natural diet is always obtained in organic forms; selenocysteine (found in organ meats) or selenomethionine (found in plants). Pet food manufacturers add inorganic sodium selenite in an attempt to provide adequate amounts of selenium. However, natural forms of selenium are more easily absorbed, utilized and stored by the body than the inorganic chemical sodium selenite.

 Scientists are still investigating how the body needs and uses various trace minerals. Selenium and other trace minerals such as chromium, boron, manganese, molybdenum, vanadium, copper, zinc and iodine, are best obtained through a healthy diet of whole foods, and not as the synthetic, inorganic supplements which are usually added to pet foods.

FLUORIDE

 Recently, I read an article about potential harm due to fluoride (fluorine), another mineral  which is inadvertently included in most all commercial pet foods. Fluoride may possibly be a contributing factor in hip and elbow dysplasias, spinal dysplasias, and osteosarcomas (the most common type of bone cancer). Fluoride is deposited in bones. How do pet foods manage to include large amounts of fluoride? By the use of added mineral supplements: phosphate rock, mono and tricalcium phosphate. According to this article, raw phosphate contains 3-4% fluoride.

 Much research on dietary fluoride has been done with pigs, sheep, goats, chicken and cattle, but there is no such information regarding fluoride intake and the development of skeletal fluorosis in dogs and cats. Because fluoride is known to interfere with reproduction, milk production, and the general health of the breeding stock/dairy cows, there are strict regulations on how much fluoride can be in the food of farm animals. But there is no fluoride intake criteria for pets. This is another demonstration of how a natural diet is preferable to one that includes inorganic minerals such as raw phosphate.

 There are thousands of different vitamins, minerals, enzymes and antioxidants. There are over 4000 different known flavonoids, a class of antioxidants found in fruits and vegetables. Vitamin A has at least 15 different forms. Vitamin E also has several different forms such as alpha, beta, delta, and gamma tocopherols.  Researchers discover new micronutrients every day. Each has a role in promoting good health. Whole, unprocessed foods contain a wide array of these micronutrients. Supplements can not match the value of whole foods.

 We (and our pets) need to obtain these micronutrients through foods, not as synthetic supplements. Synthetic vitamins are usually less efficient because they are chemically created or reduced down to one specific crystalline vitamin. During this process, the vitamin loses its synergistic components, such as mineral activators, enzymes and co-vitamin helpers. Inorganic minerals can also be less useful than their natural forms, as we noted with selenium.

 B vitamins (thiamin, riboflavin, niacin, and folate) play a key role in metabolism – they help the body release energy from protein, fat, and carbohydrates. B vitamins are also essential for a healthy nervous system.  Folate (folic acid), another B vitamin, helps the body form red blood cells. Consumption of folate reduces the risk of neural tube defects, spina bifida, cleft palate and anencephaly during fetal development.

A B-vitamin supplement may be advisable to ensure that your dog gets important vitamins such as thiamine, riboflavin, folic acid and niacin on a daily basis. B vitamins (with the exception of vitamin B-12) are water soluble and are safe to give daily.  If you cook food for your dog, the heat involved in the cooking process destroys many vitamins, so you may want to include a daily B-complex vitamin.

Vitamin C is essential for formation of collagen, and supports healthy skin and joints. Guinea pigs, humans and other primates must have vitamin C included in their diet. Dogs, however, produce vitamin C in their liver, so they do not need a dietary source of this nutrient. Dogs with liver disease may be unable to produce their own Vitamin C and may benefit from having supplemental C added to their diet. Vitamin C is water soluble, readily excreted in the urine and considered generally nontoxic. High doses of Vitamin C inhibit selenium absorption.

Vitamin C promotes the absorption of calcium, so supplementary C should be avoided in dogs with a genetic tendency to form calcium oxalate bladder stones. Vitamin C may play a role in prevention and treatment of hip dysplasia. Further studies are needed to confirm this.

Fruits and vegetables are rich in micronutrients. Whole grains may not be part of the dog’s natural diet, but they can be useful to include in small amounts since they provide many beneficial micronutrients. Wheat germ, flax seed, rice bran, as well as bee pollen, nutritional yeast, chlorella, kelp, and rose hips are rich in nutrients such as the B vitamins and vitamin E, as well as trace minerals such as iron, magnesium, selenium, iodine, zinc, copper and chromium.

In the final article in this series, we will pull all this information together, and look at various diet plans. See you next time!