Introduction

• The term "nutraceuticals" is used for compounds given orally that are legally considered neither food nor drug. It includes essential nutrients in supraphysiogical doses, such as selenium and vitamin E: extracted food compounds taken for medical purposes such as fish oils, phytochemicals and conditionally essential nutrients: enzymes and probiotics. Herbs/botanicals such as gingko biloba are generally classified as their own type of dietary supplement rather than a nutraceutical. They are generally more complex and variable than most nutraceuticals with a very different history of use.
• The North American Veterinary Council has defined a nutraceutical as: "a [non-drug] substance which is produced in a purified or extracted form and administered orally to a patient to provide agents required for normal body structure and function and administered with the intent of improving the health and wellbeing of animals".
• These novel products are very popular; it has been estimated that nearly 30% of pet owners have used or considered the use of novel ingredients for their pets. Because herbs and other novel ingredients are often perceived as natural many people also feel that they are safe and that they are a milder intervention than drugs. Many of our current drugs are originally derived from plants, eg digoxin Digoxin (originally from the foxglove plant), however the potential effects and toxicity of these products should not be underestimated.
  • The combination of Ma Huang and guarana is used in some weight loss supplements for dogs. Ma Huang contains ephedrine and guarana contains caffeine. These compounds affect the central nervous system and cardiovascular system, and in one study caused the death of 17 of the dogs given this type of product. Amanita mushrooms are also natural, and highly deadly Mushroom poisoning.
• To become licensed, drugs must undergo rigorous safety and efficacy studies, and labeling of licensed medications is highly regulated to ensure that the labeling reflects the contents of the package. Nutraceuticals do not have the same requirements. A study has shown mislabeling in 84% of nutraceutical products studied, with the amount of mislabeling ranging from 0% to 115% of the actual product in the package.
• Determining appropriate dosing for medications involves knowledge of the pharmacokinetics, or how the drug is absorbed, distributed within, and excreted from the body. With compounds such as herbs, there may be hundreds of active ingredients, making this process challenging. Determination of efficacy of the products requires measurable outcomes; a few studies in nutraceuticals have been done to try to measure these, and more scientific evidence is becoming available about some of the products. However, most nutraceutical dosages are empirical as there is insufficient data on the efficacious dose.
• The absorption, metabolism and excretion of products differ among species; therefore extrapolation from one species to another may be incorrect or unsafe. For example, lipoic acid has been used as an antioxidant in dogs, but is dangerous to use in cats.
• Antioxidants, herbs, or herbal extracts, and chondroprotectants Therapeutics: oral chondroprotectants are among the nutraceuticals used in veterinary medicine. The chondroprotectants, such as glucosamine Glucosamine and chondroitin sulfate Chondroitin sulfate are the precursors of cartilage and are sometimes used orally to support cartilage synthesis in pets with osteoarthritis Arthritis: osteoarthritis. The use of nutraceuticals as chondroprotectants Therapeutics: oral chondroprotectants has been addressed elsewhere and will not be discussed further in this component.

Antioxidants

S-adenosylmethionine (SAMe) and silybin

Fatty acids

Nutraceuticals and aging

Summary

Further Reading

Publications

Refereed papers

• Recent references from PubMed and VetMedResource.
• Webb C B, Gustafson D L, Twedt D C (2012) Bioavailability following oral administration of a silibinin-phosphatidylcholine complex in cats. Intern J Appl Res Vet Med 10 (2), 107-112 VetMedResource.
• Au A Y, Hasenwinkel J M, Frondoza C G (2011) Silybin inhibits interleukin-1β-induced​ production of pro-inflammatory mediators in canine hepatocyte cultures. J Vet Pharmacol Ther 34 (2), 120-129 PubMed.
• Skorupski K A, Hammond G M, Irish A M et al (2011) Prospective randomized clinical trial assessing the efficacy of Denamarin for prevention of CCNU-induced hepatopathy in tumor-bearing dogs. J Vet Intern Med 25 (4), 838-845 PubMed.
• Webb C B, McCord K W, Twedt D C (2009) Assessment of oxidative stress in leukocytes and granulocyte function folllowing oral administration of a silibinin-phospatidylcholine complex in cats. Am J Vet Res 70 (1), 57-62 PubMed.
• Araujo J A, Landsberg G M, Milgram N W et al (2008) Improvement of short-term memory performance in aged beagles by a nutraceutical supplement containing phosphatidylserine, Ginkgo biloba, vitamin E, and pyridoxine. Can Vet J 49 (4), 379-85 PubMed.
• Rème C A, Dramard V, Kern L et al (2008) Effect of S-adenosylmethionine tablets on the reduction of age-related mental decline in dogs: a double-blinded, placebo-controlled trial. Vet Ther 9 (2), 69-82 PubMed.
• Filburn C R, Kettenacker R, Griffin D W (2007) Bioavailability of a silybin-phostidylcholine complex in dogs. J Vet Pharmacol Ther 30 (2), 132-138 PubMed.
• Osella M, Re G, Odore R et al (2007) Canine cognitive dysfunction syndrome: Prevalence, clinical signs and treatment with a neuroprotective nutraceutical. Appl Anim Behav Sci 105 (4), 297-310 VetMedResource.
• Cupp C J, Clementine J P, Kerr W W et al (2006) Effect of nutritional interventions on longevity of senior cats. Inter J Appl Res Vet Med 4 (1), 34-50 VetMedResource.
• Roudebush P, Zicker S C, Cotman C W et al (2005) Nutritional management of brain aging in dogs. J Am Vet Med Assoc 227 (5), 722-728 PubMed.
• Center S A (2004) Metabolic, antioxidant, nutraceutical, probiotic, and herbal therapies relating to the management of heptobiliary disorders. Vet Clin North Am Small Anim Pract 34 (1), 67-172 PubMed.
• Hayek G, Massimino S P, Ceddia M A (2004) Modulation of immune response through nutraceutical interventions: implications for canine and feline health. Vet Clin North Am Small Anim Pract 34 (1), 229-247 PubMed.
• Crocenzi F A, Pellegrino J M, Sánchez Pozzi E J et al (2000) Effect of silymarin on biliary bile salt secretion in the rat. Biochem Pharmacol 59 (8), 1015-1022 PubMed.
• Boothe D M (1997) Nutraceuticals in Veterinary Medicine. Part 1. Definitions and Regulations. Compend Contin Educ Prac Vet 19 (11), 1248-1255 VetMedResource.
• Valenzuela A, Aspillaga M, Vial S et al (1989) Selectivity of silymarin on the increase of the glutathione content in different tissues of the rat. Planta Med 55 (5), 420-422 PubMed.
• Sonnenbichler J, Zetl I (1984) [Mechanism of action of silibinin. V. Effect of silibinin on the synthesis of ribosomal RNA, mRNA, and tRNA in rat liver in vivo.] Hoppe Seylers Z Physiol Chem 365 (5), 555-566 PubMed.
• Vogel G, Tuchweber B, Trost W et al (1984) Protection by silibinin against Amanita phalloides intoxication in beagles. Toxicol Appl Pharmacol 73 (3), 355-362 PubMed.

Other sources of information

• Harper J (1999) Dietary antioxidants in cat and dog nutrition. Waltham Focus 9 (2), 32.