In 2020, the global veterinary dietary supplements market size swelled to $1.6 billion; industry analysts expect that to double by 2028.¹ The human supplement market reached $35 billion last year.² The top conditions targeted for animals include joint health, liver health, immune function, and digestion.³ Obviously, these products have become big business, but how much do we know about whether they help, harm, or do anything?

Status quo

Many of us assume, or at least hope, supplement makers have a duty to demonstrate at least a modicum of safety and effectiveness before reaching store shelves. Does the United States Food and Drug Administration (FDA) oversee them all? Sort of, but their roles for human and veterinary products differ dramatically. In the end, the FDA falls far short of being able to protect either population.⁴

In fact, since 1994, following the passage of the Dietary Supplement Health and Education Act (DSHEA), the FDA has been prevented from even reviewing whether a human dietary supplement is safe or effective prior to marketing.^5,6 Underfunding and understaffing of the agency puts everyone’s health at risk.^7,8 Some lawmakers have attempted, as yet unsuccessfully, to give the FDA the teeth it needs to create better laws and enforce current ones, without much success.⁹ Human supplements are considered “legal” whereas animal supplements, by and large, are not.

First, most animal supplements, whether derived from food (nutraceuticals) or plants (botanicals), fall into the “unapproved animal drug” category.¹⁰ A product becomes an unapproved animal drug if: 1) It is intended for animals; 2) It qualifies as a “new animal drug” according to the Federal Food, Drug, and Cosmetic (FD&C) Act, and 3) It lacks legal marketing status, meaning, the FDA has neither approved, conditionally approved, nor indexed the drug. For example, as stated by the FDA, “If the intended use is to treat or prevent a disease, then the product is a drug. If the intended use is to affect the structure or function of the body and this structure or function effect is not derived mainly from the product’s nutrition, taste, or aroma, then it is a drug. Examples include a product intended to make a cat’s urine more acidic to maintain urinary tract health and a product intended to improve joint function in an arthritic dog.”¹¹

Even if the FDA considered a supplement to be an illegal, unapproved new animal drug, what happens then? The FDA states, “Unapproved animal drugs may not meet the agency’s strict standards for safety and effectiveness and may not be properly manufactured or properly labeled and packaged.”¹² What then happens to manufacturers of herbs and nutritional supplements designed for animals? Seemingly, not much. Some companies receive a warning letter outlining the infractions along with a request for further information.¹³ Does the FDA even know about all those CBD products designed for dogs, cats, and horses the local feed store sells, or the ones lining shelves at the downtown dispensary? Probably not, and, if they did, what would happen?

Industry watchdog

Enter the National Animal Supplement Council (NASC). From their website (nasc.cc), “Founded in 2001, NASC is an all-industry association of stakeholders concerned with the issues surrounding the supply of health supplements for animals not intended for human consumption, such as dogs, cats, and horses. NASC members include manufacturers of the finest animal health supplements, who are committed to the highest standards of quality and safety in the industry today, as well as raw materials suppliers, distributors, veterinarians, retailers, pet professionals, and animal friends.”¹⁴

Essentially, NASC formed in response to growing questions about the safety of animal supplements. As stated by Carrie J. Finno, DVM, PhD, “NASC does not require companies to perform efficacy studies on their products or verify that scientific research data are available proving product efficacy.”¹⁵

The yellow NASC “Seal of Quality” purports to identify “products from companies that are committed to quality, vigilance, and continuous improvement to promote the well-being of companion animals and horses.”¹⁶ Companies allowed to place the seal on their products must meet several criteria asserted by the council, including submitting a random product testing by an independent laboratory that ensures that ingredients “meet label claim.”¹⁷ Who are these independent laboratories, and how are they selected and/or regulated?

Further, NASC requires members to “have an adverse event reporting/complaint system in place to monitor and evaluate products in real time,” but does that suffice? NASC does not appear to require transparency or public disclosure of adverse outcomes for a given supplement. How much does this system actually help consumers and protect animals? How would someone know whether adverse events have happened from a supplement with a NASC seal? Was the untoward outcome diarrhea, death, or something in between? Finally, is a bottle that carries the NASC seal any more legal than one that does not?

Fortunately, a new system is emerging out of the cannabis industry, responding to calls for science, evidence, and transparency for both human and veterinary products. It is informing and transforming what we can expect from suppliers about their products’ quality, sourcing, and contents, driven by consumer demand instead of industry self-protection.

Setting new standards

Consumers are learning about and now expecting to access certificates of analyses (COAs) from hemp supplement manufacturers, including animal-targeted products.¹⁸ A COA provides a list, issued by third-party laboratories, of a sample’s contents and contaminants. This may include actual and relative amounts of cannabinoids, terpenes, heavy metals, pesticides, and more. In so doing, and when legitimately performed, a COA conveys vital insights into both the quality and batch-to-batch consistency of a product line. While testing standardization and documentation need further improvement and oversight,¹⁹ members of the public can educate themselves on ways to spot a fraudulent COA and other red flags.²⁰

Would it not be nice if other herb and supplement suppliers released reliable and trustworthy COAs to consumers for their own review, instead of trusting an industry group to police itself?

Then, once we know exactly what a product contains, what if suppliers took it upon themselves to pursue rigorous research about how their products affected each target species?

From cats and dogs to horses and parrots, we now have more knowledge about the pharmacologic and physiologic effects of hemp-derived phytocannabinoids (such as cannabidiol, or CBD) than all or nearly all other herbs and supplements. Publications from university researchers appear in PubMed.gov and other readily searchable medical databases. This means that, especially for open access publications, the public and practitioners can view the research methodologies and results for themselves instead of relying on manufacturer-provided summaries of privately performed research. Properly performed research on CBD often includes monitoring and mention of adverse events. This then becomes public knowledge instead of keeping untoward outcomes hidden.

Supplement prescribers and consumers also benefit by having access to comparative analyses, such as the analysis performed in 2020 on the cannabinoid, terpene, and heavy metal contents of 29 different CBD products.²¹ Does anything like this exist for any other class of herbal compounds for animals? No. Does it need to? Yes. In particular, for traditional Chinese medicine herbs, “Some Chinese herbal products have been found to be contaminated with undeclared plant or animal material; drugs (such as the blood-thinner warfarin and the nonsteroidal anti-inflammatory agent diclofenac); heavy metals (such as arsenic, lead, and cadmium); pesticides or compounds called sulfites, which could cause asthma or severe allergic regions; or incorrect herbs, some of which have caused organ damage.²²

However, even with all we now know about CBD science and safety, several licensing bodies in the United States continue to prevent veterinarians from even discussing CBD with clients. Doing so could risk losing one’s license,²³ and yet, no state board threatens a veterinarian with loss of license if she or he prescribes and even sells Chinese herbs—even those with secret amounts of herbal strychnine.

Narda Robinson, DO, DVM, MS, FAAMA, practices osteopathic medicine and veterinary medicine. Dr. Robinson taught science-based integrative medicine at the Colorado State University College of Veterinary Medicine and Biomedical Sciences for 20 years. In 2016, Robinson established her own academy in Fort Collins, CO, where she teaches medical acupuncture, integrative rehabilitation, medical massage, and other integrative medical approaches.

References

1. Grand View Research. Veterinary dietary supplements market size, share & trends analysis report by animal type (livestock, companion, by application, by type, by dosage form, by distribution channel, by region, and segment forecasts, 2021-2028. Accessed at https://www.grandviewresearch.com/industry-analysis/veterinary-dietary-supplements-market-report on 07/04/2023
2. AMA Journal of Ethics. Underregulated Supplements. May 2022, Volume 24, Number 5. E343-451. Accessed at https://journalofethics.ama-assn.org/issue/underregulated-supplements on 07/05/2023.
3. Grand View Research. Veterinary dietary supplements market size, share & trends analysis report by animal type (livestock, companion, by application, by type, by dosage form, by distribution channel, by region, and segment forecasts, 2021-2028. Accessed at https://www.grandviewresearch.com/industry-analysis/veterinary-dietary-supplements-market-report on 07/04/2023.
4. Charen E and Harbord N. Toxicity of herbs, vitamins, and supplements. Adv Chronic Kidney Dis. 2020;p27(1):67-71.
5. United States Food & Drug Administration (USFDA) Website. FDA’s Regulation of Pet Food. Accessed at https://www.fda.gov/animal-veterinary/animal-health-literacy/fdas-regulation-pet-food on 07/04/2023.
6. Consumer Healthcare Products Association. A look back at DSHEA, 27 years later. October 25, 2021. Accessed at https://www.chpa.org/news/2021/10/look-back-dshea-27-years-later on 07/04/2023.
7. Alphonse J, Bellam S, Fernandez M, et al. The FDA funding crisis. J Pharm Technol. 2014; 30(2):57-60.
8. United States Food & Drug Administration (USFDA) Website. FDA News Release. FDA seeks $8.4 billion to further investments in critical public health modernization, core food and medical product safety programs. March 28, 2022. Accessed at https://www.fda.gov/news-events/press-announcements/fda-seeks-84-billion-further-investments-critical-public-health-modernization-core-food-and-medical on 07/04/2023.
9. The Editors. We need to better regulate nutraceuticals. Scientific American. June 1, 2023. Accessed at https://www.scientificamerican.com/article/we-need-to-better-regulate-nutraceuticals on 07/04/2023.
10. United States Food & Drug Administration (USFDA) Website. Unapproved Animal Drugs. Accessed at https://www.fda.gov/animal-veterinary/compliance-enforcement/unapproved-animal-drugs#Unapproved on 07/04/2023.
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16. National Animal Supplement Council. Profile. Accessed at https://www.nasc.cc/nasc-seal on 07/04/2023.
17. National Animal Supplement Council. Profile. Accessed at https://www.nasc.cc/nasc-seal on 07/04/2023.
18. ElleVet Website. ElleVet Sciences Certificate of Analysis (COA) Library. Accessed at https://www.ellevetsciences.com/coa on 07/05/2023.
19. Henlon J, Evans S, and Wakshlag JJ. Key quality control aspects about cannabinoid-rich hemp products that a veterinarian needs to know: a practitioner’s guide. JAVMA. July 2023. 261(7):1054-1060.
20. Bennett T. How to pick out fraudulent and misleading COAs with Kia Mikesh of Adams Independent Testing. Cannabis Business Times. May 8, 2020. Accessed at https://www.cannabisbusinesstimes.com/news/how-to-pick-out-fraudulent-false-misleading-coas-hemp on 07/05/2023.
21. Wakshlag JJ, Cital S, Eaton SJ, et al. Cannabinoid, terpene, and heavy metal analysis of 29 over-the-counter commercial veterinary hemp supplements. Vet Med (Auckl). 2020; Apr 15;11:45-55.
22. National Center for Complementary and Integrative Health Website. Traditional Chinese Medicine: What You Need to Know. Accessed at https://www.nccih.nih.gov/health/traditional-chinese-medicine-what-you-need-to-know# on 07/05/2023,
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