{"id":1046,"date":"2014-05-01T01:05:07","date_gmt":"2014-05-01T01:05:07","guid":{"rendered":"http:\/\/phosdev.com\/todaysveterinarypractice\/?p=1046"},"modified":"2022-02-16T16:10:25","modified_gmt":"2022-02-16T16:10:25","slug":"acvn-nutrition-notes-surveying-supplements-current-trends-research-recommendations","status":"publish","type":"post","link":"https:\/\/navc.sitepreview.app\/todaysveterinarypractice.com\/nutrition\/acvn-nutrition-notes-surveying-supplements-current-trends-research-recommendations\/","title":{"rendered":"Surveying Supplements: Current Trends, Research, & Recommendations"},"content":{"rendered":"

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Justin Shmalberg, DVM, Diplomate ACVN, University of Florida<\/em><\/p>\n

More and more pet owners are asking veterinarians for advice on dietary supplements for their pets. The author provides guidance on the use of vitamins and minerals, fatty and amino acids, and herbal supplements.<\/p>\n

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The American College of Veterinary Nutrition<\/strong> (acvn.org) designates specialists in veterinary nutrition, provides continuing education, supports veterinary nutrition residency programs, and offers a wide array of resources related to veterinary nutrition. By bringing this column to TVP<\/em> readers, the ACVN is reaching out to veterinary professionals to provide the highest-quality, cutting-edge information on companion animal nutrition, contributed by their foremost nutrition specialists.<\/p>\n<\/div>\n

V<\/span>eterinarians frequently encounter the use of dietary supplements in clinical practice. The exact prevalence of supplementation by pet owners is unclear, but economic indicators suggest the practice is widespread.<\/span><\/p>\n

Estimated annual expenditures by American owners reached over $1 billion in 2010, with 31% of dog owners and 22% of cat owners reporting use of such products.1<\/sup> A 2006 nutritional survey found that 9.9% of pet owners administered dietary supplements; most prevalent were multivitamins, joint supplements, and fatty acids.2<\/sup><\/span><\/p>\n

Limited data are available on particular products, but veterinarians should be aware of:<\/span><\/p>\n

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  1. Owners\u2019 rationale for supplementation<\/span><\/li>\n
  2. Regulation of dietary supplements<\/span><\/li>\n
  3. Possibility of adverse effects<\/span><\/li>\n
  4. Theoretical or scientific basis of common ingredients encountered in products.<\/span><\/li>\n<\/ol>\n

    OWNER RATIONALE<\/span><\/h2>\n

    While no definitive studies on the psychology of pet supplement use exist, clinical experience suggests that dietary additive use is based on several reasons:<\/span><\/p>\n

      \n
    1. Perceived deficiencies in commercial pet foods and\/or distrust regarding food formulation<\/span><\/li>\n
    2. Preference for treatments marketed as \u201cnaturally\u201d derived and safe, with few side effects<\/span><\/li>\n
    3. Belief that integration of dietary supplements and pharmaceutical drugs is more efficacious than the latter alone, and that these supplements may prevent drug side effects<\/span><\/li>\n
    4. Perceived reduction in disease morbidity or mortality, such as chondroprotectants to prevent\/treat joint disease and dietary supplements to increase survival times in oncologic patients.3<\/sup><\/span><\/li>\n<\/ol>\n

      ADVERSE EFFECTS<\/span><\/h2>\n

      The safety profiles of most supplements are only anecdotally established. Adverse events from minerals and vitamins are well described and occasionally seen with high doses, while adverse events from herbal medications and extracted compounds generally occur due to one of the following:<\/span><\/p>\n

        \n
      1. Idiosyncratic or unpredictable interactions; for example, interactions have been reported between nutraceuticals, herbs, and drugs4<\/sup><\/span><\/li>\n
      2. Off-label use, dose, or combination of these dietary additives5-8<\/sup><\/span><\/li>\n
      3. Inappropriate processing or misidentification of products9<\/sup><\/span><\/li>\n
      4. Contamination\u2014intentional or inadvertent\u2014and variability in ingredients and their concentration10-13<\/sup><\/span><\/li>\n<\/ol>\n

        COMMON SUPPLEMENTS<\/span><\/h2>\n

        Vitamins & Minerals<\/span><\/h3>\n

        The recommended allowance of nutrients in most commercial pet foods is guided by current Association of American Feed Control Officials (AAFCO) standards and the National Research Council\u2019s (NRC) assessment of the scientific literature.14<\/sup> <\/span>Table 1<\/span><\/strong> lists common vitamin and mineral supplements.<\/span><\/p>\n

        Commercial Foods. <\/span><\/strong>Commercial pet foods are replete with vitamins and minerals. Only in rare circumstances\u2014generally due to underlying pathology\u2014do pets fed commercial AAFCO-labeled foods require additional minerals and vitamins. Oversupplementation may be deleterious; administration of excessive dietary calcium during growth of large breed dogs may predispose to development of orthopedic disease.14<\/sup><\/span><\/p>\n

        Home-Prepared Foods. <\/span><\/strong>Many home-prepared diets require vitamin and mineral supplementation. In general, human multivitamins are recommended because they are designed to complement the foods used in these diets. Multivitamins designed for pets are generally formulated to supplement commercial pet foods and to prevent toxicity by providing lower amounts of nutrients.<\/span><\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n
        Table 1. Common Vitamins & Minerals Administered by Owners<\/strong><\/td>\n<\/tr>\n
        NUTRIENT<\/td>\nSUMMARY<\/td>\n<\/tr>\n
        Minerals<\/strong><\/td>\n<\/tr>\n
        Calcium<\/td>\n\u2022 Calcium requirements for adult maintenance are low; additional supplementation does not provide much benefit.
        \n\u2022 Avoid low, or high, calcium intake in growing animals.
        \n\u2022 Carefully and deliberately supplement calcium only (1) in rare instances or (2) for animals on low-calcium, home-prepared diets.<\/td>\n<\/tr>\n
        Selenium<\/td>\n\u2022 It is often administered to pets with cancer, but insufficient data exists supporting its use for cancer treatment or prevention in humans and animals.15<\/sup><\/td>\n<\/tr>\n
        Zinc<\/td>\n\u2022 Owners may supplement due to perceived benefits for immune function or dermatologic disease.
        \n\u2022 Benefits are unlikely unless the animal (1) is fed a high-fiber diet low in zinc or (2) has a genetic predisposition for deficiency (northern breeds).<\/td>\n<\/tr>\n
        Vitamins<\/strong><\/td>\n<\/tr>\n
        B-Complex Vitamins<\/td>\n\u2022 These vitamins are minimally toxic, and significant excesses are present in most commercial foods.
        \n\u2022 Certain hereditary and pathological conditions result in vitamin B12 deficiency, but supplementation of B vitamins in normal animals is not<\/em> likely beneficial.<\/td>\n<\/tr>\n
        Vitamin C<\/td>\n\u2022 Vitamin C is synthesized from glucose in dogs and cats.
        \n\u2022 High amounts of vitamin C can induce lipid peroxidation, which may be the basis for anecdotal reports of high-dose, IV vitamin C for cancer treatment.
        \n\u2022 Vitamins C and E (50 mg\/kg, each) decreased cisplatin-induced vomiting episodes in dogs.16<\/sup>
        \n\u2022 Supplementation has been shown to increase serum or plasma levels; in one study, it increased cartilage weight in experimental canine arthritis.14<\/sup>
        \n\u2022 Supplemented greyhounds ran slower when given vitamin C, and diarrhea has been reported.14<\/sup>
        \n\u2022 Most canine studies administered 1 g of supplemental vitamin C.<\/td>\n<\/tr>\n
        Vitamin D<\/td>\n\u2022 Dogs and cats produce little vitamin D in the skin and, therefore, require dietary intake or supplementation (unlike humans).14<\/sup>
        \n\u2022 Commercial diets include vitamin D or contain organ meats rich in fat-soluble vitamins.
        \n\u2022 Deficiencies of vitamin D in home-cooked and raw diets have been reported.17<\/sup>
        \n\u2022 A relationship between low vitamin D and neoplasia has been reported in dogs with mast cell tumors compared to controls,18<\/sup> but a causal link has not yet been identified.
        \n\u2022 Supplementation in animals consuming commercial pet foods is not recommended, and may cause toxicity (bone growth abnormalities, mineralization, hypercalcemia).<\/td>\n<\/tr>\n
        Vitamin E<\/td>\n\u2022 Supplementation of polyunsaturated fatty acids generally increases vitamin E requirements.14<\/sup>
        \n\u2022 Vitamin E has been recommended for canine osteoarthritis (OA) (400 IU\/day),19<\/sup> hepatic disease,20<\/sup> atopic dermatitis, and other inflammatory conditions.
        \n\u2022 Data is strongest for arthritis, but doses used have been variable (generally 10\u201320 IU\/kg).
        \n\u2022 High doses may impair blood clotting.14<\/sup><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

        Fatty Acids<\/span><\/h3>\n

        Fatty acids have received extensive attention in the human and veterinary literature. Most mammals synthesize saturated fats, but lack the ability to produce the omega-3 and omega-6 series of polyunsaturated fatty acids. Therefore, dietary sources of these essential fatty acids are required. A summary of relevant polyunsaturated fatty acids is provided in <\/span>Table 2<\/span><\/strong>.<\/span><\/p>\n\n\n\n\n\n\n\n\n
        Table 2. Relevant Polyunsaturated Fatty Acids<\/strong><\/td>\n<\/tr>\n
        FATTY ACID<\/td>\nSUMMARY<\/td>\n<\/tr>\n
        Alpha Linolenic (n-3)<\/td>\nMay be essential in dogs and cats but data is lacking<\/td>\n<\/tr>\n
        Docosahexaenoic (n-3)<\/td>\nMay exert biologic effects, specifically in the retina and neural tissues<\/td>\n<\/tr>\n
        Eicosapentaenoic (n-3) & Arachidonic (n-6)<\/td>\n\n
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        • Arachidonic acid<\/strong> products generally promote inflammation and platelet aggregation.<\/li>\n
        • EPA<\/strong> produces less potent prostaglandins and leukotrienes.<\/li>\n<\/ul>\n

          Proposed effects include:21<\/sup><\/p>\n

            \n
          • Improved renal parameters in experimentally induced kidney disease<\/li>\n
          • Reduction of inflammation in OA; mild to modest decreases in lameness and NSAID requirements were noticed in clinical trials of therapeutic diets with EPA and DHA22<\/sup><\/li>\n
          • Decreased very-low-density lipoprotein in hyperlipidemia, pruritus and\/or dermatitis, and cardiac cachexia and arrhythmias in heart disease<\/li>\n
          • Chemosensitization and improved oncologic survival<\/li>\n
          • Improved memory and learning in puppies.23<\/sup><\/li>\n<\/ul>\n<\/td>\n<\/tr>\n
        Linoleic (n-6)<\/td>\nEssential fatty acid in dogs and cats<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

        Feline Requirements. <\/span><\/strong>Delta-6 desaturase is an enzyme that adds an additional double bond to linoleic and alpha linolenic acids, starting a conversion process to longer, more unsaturated products. Cats, however, possess very low levels of this enzyme, which creates their conditional requirement for arachidonic acid in growth, lactation, and gestation.<\/span><\/p>\n

        Dosage.<\/strong> <\/span>Doses of fish oil used to provide certain omega-3 fatty acids vary in relevant studies. Many conditions responded to doses approximating an intake of 1 to 1.5 mg of eicosapentaenoic acid and docosahexaenoic acid (EPA+DHA) per calorie, and most standard fish oil capsules contain 300 mg of EPA+DHA.<\/span><\/p>\n