Consumers are taking greater responsibility for their own health by turning to nutritional supplements and functional foods and beverages that offer greater natural health benefits and fewer synthetic ingredients. A recent survey in Consumer Reports showed that nutrition is the top concern driving their food and health purchasing decisions.

The food, beverage and supplement marketers have responded with a barrage of products supported with extensive advertising, scientific-sounding label claims and educational literature. Likewise, pet product companies are also responding with a vast array of specialty foods, treats and therapeutic supplements for dogs, cats, horses, ferrets and reptiles.

According to the State of the American Pet Survey, a study of 2001 dog and cat owners sponsored by the Health Pets 21 Consortium (a think tank recently established by the Purina Pet Institute and Ralston Purina Company), one of the greatest challenges of pet ownership is maintaining pets' health. The survey also found that 41% of pet owners had considered or tried various alternative therapies, including nutritional supplements (29%), herbal remedies (7%) and homeopathy (4%).

In the past, pet owners chose animal products on the basis of packaging design, advertising claims, cost and convenience. Today, they are feeding their pets highly digestible, energy-dense foods and specialty treats so that their animals look and feel better and may even live longer. However, even highquality premium foods may not always be enough to promote optimum health and vitality for every animal.

Every animal, depending on condition, age, temperament and lifestyle, has unique nutrient requirements. Fine-tuning pet foods with nutritional supplements either as standalone products or by incorporating specific nutrients into the food itself provides an integrated and holistic approach to addressing individual needs. Using premium foods and vitamins, minerals and so-called nutraceuticals can enhance vitality and prevent or treat certain diseases. But which nutrients are actually beneficial? Which are wasteful? Worse yet, which are detrimental to pet health and owners' pocketbooks? Should certain ingredients be incorporated routinely into pet foods and will they consistently achieve the desired health effects?

The Pet Market
Trends in pet foods and supplements have paralleled those in beverages, foods and supplements designed for human consumption. Pets owners are now encouraged to feed their pets better foods, exercise them more often and give them supplements. Even trends in the pet and human nutraceutical industry mirror each other as fewer power players dominate the two channels. For example, two large natural food retail chains, Wild Oats and Whole Foods, dominate the natural sector more than 300 stores selling almost $3 billion annually. In the pet area, PETCO and PetSmart's combined 1000 retail outlets sold $3.8 billion in pet care products last year, including $1.4 billion of pet foods and supplements.

According to a recent report released by the market research firm Business Communications Company, Norwalk, CT, sales of pet foods, supplements, supplies, veterinary services, boarding and grooming will reach $33.5 billion by 2005. The North American pet food sector (currently valued at $12.8 billion) will reach $15.7 billion, although the annual growth rate will slow to 4.1%, down from the 15-18% witnessed in the 1990s. Supplement sales are predicted to reach at least $1 billion with growth projected at 17-22%. According to Nutrition Business Journal (March 2000), sales of natural pet products are expected to top $.5 billion by 2005, although these products accounted for only 1.3% of total natural food store sales last year.

Pet Product Regulations
Accompanying the growth in sales of human dietary supplements is an increasing interest in pet nutraceuticals. The North American Veterinary Nutraceutical Council now defines a veterinary nutraceutical as a "non-drug substance that is produced in a purified or extracted form and administered orally to provide agents required for normal body structure and function with the intent of improving the health and well being of animals." Nutraceuticals and similar products are being evaluated in veterinary schools to determine the merit of their claims.

Pet and natural food stores as well as many veterinary hospitals and Internet direct sales companies display a wide array of pet dietary supplements, along with pet foods and other products. However, before purchasing pet supplements, owners need to make sure these dietary products are truly helpful, safe and effective and that they have undergone many of the same scientific and clinical evaluations that are now required of human nutritional supplements. Owners and retailers must also realize that the FDA's DSHEA legislation, which governs human dietary supplements, does not apply to animals. Pet products are regulated under the auspices of specific animal regulatory agencies.

The Association of American Feed Control Officials (AAFCO) was established years ago by state chemists to provide ingredient guidelines to the manufacturers and marketers of animal food products. However, AAFCO provides no direction as to claims permitted for nutritional products. Several years ago in response to this void, AFFCO appointed a Nutraceutical Regulatory Advisory Panel to draft a national consensus regulating the use of nutraceuticals in animal foods. Unfortunately, the panel has yet to complete a document that would establish any framework or reference point for further implementation.

The Center for Veterinary Medicine (CVM), the part of FDA responsible for enforcing all the provisions of the Food, Drug and Cosmetic Act (FDCA) as they apply to animals, was recently created to oversee labeling claims and to evaluate product utility. But the CVM has assigned a "low regulatory significance" to most pet nutraceuticals and largely relies on AAFCO and the states to deny or approve market access to nutraceuticals. Confusing? You bet!

There is certainly a need to regulate the safe use of effective dietary supplements for animals as well as accurate structure/function claims. But until regulatory agencies reach a consensus based on science rather than anti-supplement bias or misinformation, pet owners, veterinarians and retailers must take responsibility for educating themselves.

Most pet supplement marketers and manufacturers have a clear empirical sense of what works and what does not. However, the expense of clinical trials, lack of regulatory standards and costs of countering "me-too" products make it extremely difficult to justify the costs of substantiating product claims. Only the largest companies can finance clinical trials and in vitro studies, and only these companies have the influence or persistence to obtain favorable rulings from regulatory agencies. A case in point is the ruling on inclusion of glucosamine in IAMS® Senior dog food and its acceptance by the state of Texas, notorious for its tough rules. Companies have the power to self-regulate and must do so to prevent the sale of harmful or "do-nothing" products.

According to Guy Miller, president, Galileo Labs, Santa Clara, CA, which has a joint venture with P&G's IAMS division and provides analytical methods for nutrient determinations in pet food, four elements are often missing from functional pet foods or supplements that promise nutraceutical-type properties:

1. Demonstrated safety and efficacy: There are currently no standards for labeling or dosing of bioactive ingredients.

2. Third-party credibility: Scant data support the mechanism of action of many dietary supplements, leading veterinarians, researchers and influencers to remain unconvinced and unsupportive.

3. Defensible intellectual property: Weak patents preclude the sustainable competitive advantage available to human pharmaceutical manufacturers.

4. Enabling regulatory path: Regulatory oversights and confusion provide minimal product liability protection.

Nutraceutical Pet Products
Despite these caveats, there are numerous high-quality and efficacious nutraceutical ingredients and nutritional supplements for animals. Marketing the relationship between pet health and nutrition has become more finely tuned and sophisticated, as additional nutrient clusters are identified that serve as alternative means to treat or prevent animal diseases. There has been acceptance among veterinarians that many of these products will benefit animal health if used judiciously and intelligently. The following is a brief discussion of some of the more popular categories of pet dietary supplements.

Joint Health: Because of better foods, feeding practices and veterinary care, animals-like humans-are living longer and feeling better in their advanced age. As animals live longer, however, they are prone to genetically influenced degenerative conditions such as canine hip dysplasia, intervertebral disk disease and inherited hemotologic disorders, as well as non-specific aches and pains. Pet food and supplement manufacturers have responded with a multitude of specialty foods and supplements containing glucosamine, chondroitin sulfate, MSM, green-lipped mussel and yucca in a variety of combinations.

Efficacy claims are sometimes vague or anecdotal, and purchases are often based on which product has the best-designed label, the most appealing package or the most persuasive advertising. On the other hand, there is ample evidence-sometimes anecdotal-that many of these products have a beneficial effect on joint health. Many of the active ingredients found in oral joint supplements for pets really do work.

Glucosamine is a component of glycosaminoglycans (GAGs) found in joints, tendons, ligaments, skin and blood vessels. GAGs are comprised of long chains of modified amino sugar molecules that capture water and allow cartilage, for example, to adapt to pressure changes in the joint capsule, acting as a shock absorber during mechanical stress. When cartilage begins to break down from overuse, age or disease, the lubricating GAGs are destroyed and lose their shock-absorbing properties.

Providing supplemental glucosamine to joint tissues stimulates them to produce more GAGs. There have been numerous studies of human and animal tissues that have shown that glucosamine is readily incorporated, without modification or degradation, into GAGs. Although glucosamine can be synthesized within tissues, exogenous glucosamine is an indistinguishable substrate for the biosynthesis of GAG molecules. In this regard, glucosamine in any of its commercial forms (chloride, sulfate or free) can be considered a conditionally essential nutrient.

Chondroitin sulfate, a linear carbohydrate polymer that also contains glucosamine molecules, is a specific type of GAG found in joint cartilage. It attracts water into its fibrous matrix, nourishing the cartilage and enabling it to protect joint structures under compressive loads. Chondroitin supplements can slow the process of degradation in a diseased joint by binding up and neutralizing some of the destructive enzymes. It also may stimulate the body to produce additional substrates important for a healthy joint. Chondroitin can be extracted commercially in a highly heterogeneous form from animal cartilage or connective tissue, most commonly bovine tracheal tissue. Extracts of shark cartilage, perna mussel or sea cucumber are also used.

One proprietary product, a blend of glucosamine HCl, chondroitin sulfate and manganese ascorbate, is sold only through veterinarians and has been the subject of several cell culture/animal model veterinary trials. In a survey of more than 3000 veterinarians, the product was rated good to excellent in reducing pain, improving mobility and improving attitude in more than 80% of the animals receiving the product.

Glucosamine and chondroitin sales in 1999 were estimated at $1.27 billion. Although long accepted in Europe, glucosamine was introduced into the U.S. as a dietary supplement for humans only as recently as 1993. Veterinarians and pet owners have been treating joint dysfunction in dogs and horses with glucosamine and chondroitin for some time in the U.S.

In hopes of improving the performance of glucosamine and/or chondroitin products, some pet product manufacturers add methylsulfonylmethane (MSM), a source of organic sulfur thought to be important in helping the body form a strong collagen matrix; trace minerals such as copper, manganese and zinc that play active roles as co-factors in enzymatic reactions; boswellia (frankincense), a gum resin shown to have anti-inflammatory properties and Ester-C© ascorbates, non-acidic forms of vitamin C that have anti-inflammatory and analgesic properties as well as being essential for the formation and maintenance of collagen. Some supplements also contain other anti-inflammatory additives such as devil's claw or white willow bark, which reduce pain symptoms but do not treat the cause.

Free Radical Damage: Pets continually produce free radicals during everyday normal activities such as eating, breathing, walking or even sleeping. Production of free radicals increases dramatically with exercise, stress, disease and age. The resulting damage can affect cell membrane integrity, the immune system and the fidelity of the genetic apparatus, as well as many degenerative conditions and aging. It is known that excessive formation of free radicals is a byproduct of oxidative damage. These can overwhelm an animal's defense system, resulting in diseases such as feline immunodeficiency virus (FIV), a viral infection similar to HIV in humans. Free radicals are also thought to aggravate genetically predisposed conditions such as canine hip dysplasia (CHD), chronic obstructive pulmonary disorder (COPD, or asthma) or arthritis.

Antioxidants such as vitamins C and E, beta-carotene and selenium protect dogs and cats by slowing the aging process through neutralizing the effects of these free radicals. Researchers have found that antioxidants can produce significant declines in FIV replication as well as increased cell death in cultured infected feline blood cells. Although dogs manufacture their own vitamin C, the amounts may not be sufficient to counter these free radical effects under certain conditions. Studies on vitamin E in dogs have shown the influence of this nutrient on immune cell responsiveness and the ability to fight exercise-induced oxidative stress. Dr. Ronald Schultz of the Madison School of Veterinary Medicine at the University of Wisconsin has demonstrated that vitamin E deficiency in dogs reduces responses to vaccines and increases susceptibility to infection.

Allergies And Skin Dysfunctions: Omega 3 fatty acids are derived mainly from flaxseed oil and fish oil in the diet. Unlike the omega 6 fatty acids, they are used preferentially for select functions, such as proper brain development and reduced inflammatory response. The use of omega 3 fatty acids in pet foods and supplements may help reduce the signs of allergies and other skin inflammatory dysfunctions such as itching and reddening. Veterinarians often advocate the use of omega 3 fatty acids as routine supplements for dogs or cats with non-specific skin problems, although a proper diagnosis often requires an expensive in-depth diagnostic work-up. The ratios of omega 3 to omega 6 fatty acids and the total amount of fat intake affect response, and their inclusion in the diet must be carefully balanced.

Other: St. John's Wort, Rescue Remedy, green food products, probiotics and other supplements also address dietary deficiencies and pet owners' needs. Unfortunately, such products will simply remain on the shelves of pet specialty stores unless informed store personnel understand their value and can educate pet owners on their correct usage. In natural products stores, these supplements are often relegated to "back-of-the-store" shelves where they sit quietly among environmentally friendly paper towels and diapers, collecting dust.

Fortified Pet Foods
Pet foods are increasingly fortified with some of the more common nutraceuticals such as omega-3 fatty acids, glucosamine, chondroitin sulfate, L-carnitine, antioxidants (vitamins C and E, beta-carotene, selenium), prebiotics and probiotics, and herbs such as gingko, St. John's wort and garlic. Nutrient-enhanced treats are also appearing in pet, mass, grocery and natural food stores.

Dr. David Dzanis, a board-certified veterinary nutritionist who formerly served with FDA, feels that the addition of nutraceuticals and other "bells and whistles" to pet foods is likely to grow, although he is concerned that the science to support these new uses "is insufficient to support claims."

Nutrition Business Journal (October 2000) recently reiterated a concern voiced by many supplement manufacturers: "Consumers may be replacing standalone supplements with fortified, or functional foods and beverages. Most premium pet foods have always been considered more functional (lifestyle or life-stage specific) than the average American's diet. The addition of ingredients with purported nutraceutical properties to foods and beverages has left a lot of pet owners both hopeful and confused."

Are the levels of nutrients actually consumed by pets really effective? Are these nutrients stable enough to withstand the high temperatures of extrusion, cooking or baking? Do they maintain their activities during prolonged storage? What about the heating and cooling that occur in retail stores? All of these questions have yet to be satisfactorily answered in spite of the flood of nutraceuticals added to pet foods such as those from IAMS (owned by Proctor & Gamble), Science Diet (owned by Colgate-Palmolive), Waltham and Alpo.

Other important questions are: How will the promise of a nutraceutical benefit affect the sales of standalone supplements? Will the owner of an old, lame dog, for example, seek the relief of glucosamine in a senior formula rather than a pill or powder? Does chicory really help your dog digest food better? Does Hill's Science Diet Healthy Defense™ System really provide optimum levels of antioxidants to protect your dog against the risk of disease? Pet supplement companies say "No!" Pet food companies say, "Yes!" What is the best approach for your pet?

Mike Gurber, vice president, Precise Pet Foods, Nacogdoches, TX, is one of many pet product manufacturers who has voiced concern. "Product stability and the quality of raw ingredients are very critical concerns," he said. "It is incumbent upon the manufacturers to determine beyond a doubt that their product contains the stated amount of nutraceutical, not only at the time of manufacture, but throughout the acknowledged shelf life of the contents. To do less is unacceptable."

Another worry is whether the levels of nutraceutical ingredients that are actually consumed by a pet are sufficient to produce the desired effect, and what effect these ingredients would have on the general pet population if routinely consumed. Dr. Todd Henderson, vice president, Nutramax Laboratories, Edgewood, MD, feels that such questions should be based on clinical studies and answered by veterinarians and animal nutritionists rather than marketers and salespeople. Charles Frank, president, PetMax Naturals, Westlake Village, CA, is also concerned with the use of nutraceuticals in pet foods. He said, "There is no doubt that certain compounds will benefit animal health when used properly. But will people stop using specific ingredients already shown to be beneficial in favor of the shotgun approach? And what of the dogs or cats that don't really require the nutrient now? What happens later when it might be helpful? Will it still work?". These questions remain unanswered.

Because of the regulatory vacuum in which pet supplements exist, product labels can only provide standard descriptions of each ingredient. Labels do not and cannot indicate value. Those with demonstrated efficacy but unsupported by in-depth clinical trials or cell/animal model studies continue to rely on the pet owners' belief that the products will benefit their animals. Companies that do provide substantiating studies must avoid promoting with "prevent and treat" claims because they are not protected by DSHEA and could be targeted by over-eager AAFCO or CVM agents. Recently, a CVM official advised a veterinarian who runs a well-respected pet product company that the use of a certain ingredient was not approved. The reason given: "The ingredient in question, if consumed by a pet that could be killed by a car and subsequently transported to a food processing plant, might end up as part of a fast food burger." This official explanation seems inane and is an overly contrived way to reject an ingredient that might benefit an animal.

Unfortunately, without sage regulatory advice or guidance, pet owners, veterinarians and retailers must rely on each company's labels, ancillary literature, sales reps and other feedback to provide insight into product efficacy.

Natural food retailers have not yet seized the opportunity to promote pet products in their stores. At least 60% of their customers are dog and/or cat owners who often buy natural pet foods and supplements at pet superstores where personnel understand the use of these products and are trained in their application. These are the same stores that offer a huge variety of pet nutritional supplements along with natural pet foods, shampoos and flea control products. Pet stores support such products with signage, samples, in-store demos and animal events, providing plenty of shelf space in high-traffic areas.

Conclusion
There is no doubt that complementary and alternative medicine are changing the face of pet health care. It is also challenging some basic assumptions. The new paradigm is that animals cannot get optimum nutrition from their food alone. According to Jamie Brooks, marketing manager, Vitaflex Nutrition, Waterbury, VT, "The move to normalize and legitimize animal nutraceuticals will lead the way to responsible practices." Ms. Brooks said she feels that most misinformation is due to ignorance, not greed, and that most animal-oriented companies do have a sense of what works.

Companies that add nutraceutical-type ingredients such as joint support nutrients, antioxidants or digestive aids must make sure that these ingredients are not inactivated during processing or storage and are present quantitatively in the product at the time of consumption, not just noted qualitatively as ingredients on the label. Furthermore, pet owners and vets who recommend products should research the active ingredients in supplements and foods to ensure their animals receive the same quality they expect for themselves.

Although there is increased interest in specific nutrients or nutrient clusters, veterinarians have not routinely embraced supplements for animals. Nevertheless, nutraceuticals, supplements and additives will play an increasingly important role in preventing and managing animal diseases. As this happens, pet product companies must commit to providing solid evidence of safety and efficacy as well as dosages that ensure benefit. As Dr. Jane Bicks, a leading advocate of natural pet health care, says, "Doing no harm is paramount. Our pets deserve it. But doing good is the best." NW

About the author:
Dr. Brown is the Ester-C Product Manager for Inter-Cal Nutraceuticals. Prior to joining the company he was a small animal veterinarian in Cape Cod, MA, and developed and marketed natural foods, supplements and treats for dogs, cats and horses. He can be reached at Inter-Cal Nutraceuticals, 6735 Inter-Cal Way, Prescott, AZ 86301; 520-445-8063; Fax: 520-778-7986; E-mail: p_brown@intercal.com; Website: www.intercal.com.

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