GettyImages/Prostock-Studio The use of nutritional supplements by clients and veterinarians has expanded dramatically over the past decade, reflecting a broader cultural shift in which pet owners increasingly view their animals as integral family members. Pet owners are seeking proactive strategies to optimize the health and longevity of both themselves and their pets. The overall use of human supplements was estimated at 51.8 percent of adults in 2011-2012, which increased to 61.4 percent in 2021-2023.1 A recent market analysis estimated the global pet supplement market size to be approximately $2.8 billion in 2025 and is estimated to register an annual growth rate of 8.1 percent to reach $5.6 billion by 2034.2 Interest has been fueled by aggressive marketing and the proliferation of online retail platforms, with messaging that “natural” or “holistic” products are inherently safer or more beneficial than conventional therapeutics. Top-selling products focus on mobility/hip and joint support, skin and coat health, cognition/brain health, and behavior/anxiety.3 Veterinary practitioners are increasingly confirming that their patients are receiving multiple supplements concurrently, often without veterinary guidance or a clear therapeutic rationale. The supplement marketplace encompasses a wide range of product formulations, including chews, powders, capsules, tinctures, and food toppers, each promoted for its targeted benefits. Some of these products contain ingredients with researched mechanisms of action or emerging evidence of efficacy, but many others rely on extrapolated data, anecdotal reports, or marketing narratives that may outpace or stretch the available science. With marketing, a discrepancy may be created between consumer perception and scientific validation, which underscores the need for veterinarians to maintain a proactive and critical, evidence-based approach when evaluating supplement use in clinical practice. Following the trend in human health, supplement development is also being integrated with technology, and pets now have wearable devices to track location from global positioning systems along with health metrics. Data collected can now measure temperature, pulse, heart rate variability, respiratory rate, activity, calories, and posture changes along with various behaviors such as scratching, licking, sleeping, eating, drinking, running, walking, and resting, This data can be then used to monitor general health and to drive nutritional and supplement recommendations.4-6 Pet supplements come in a range of dosage forms—including chewable tablets, powders, and flavored chews—with product labels listing active ingredients by dose (milligrams or grams). Small kitchen teaspoons can help measure very small quantities, and empty capsules are commonly used to load and deliver powdered supplements. PHOTOS COURTESY WHOLE PET PROVISIONS, PLLC, PHOTO DATABASE Who regulates them? Unlike pharmaceuticals, which undergo rigorous pre-market evaluation for safety, efficacy, and manufacturing quality, most animal supplements fall into a regulatory gray zone. The U.S. Food and Drug Administration (FDA) regulates human dietary supplements through the Center for Food Safety and Applied Nutrition (CFSAN) under the Dietary Supplement Health and Education Act (DSHEA) of 1994, which defines supplements as oral products containing dietary ingredients such as vitamins, minerals, botanicals, amino acids, or metabolites. The term “dietary supplement” legally applies only to human products, while “nutraceuticals” have no FDA regulatory definition.7 In contrast, the FDA Center for Veterinary Medicine (CVM) oversees animal food products and food additives, which must be approved unless they are generally recognized as safe. Any animal product claiming to treat, cure, prevent, or mitigate disease is legally considered a new animal drug. Pet food and treats fall under the Association of American Feed Control Officials (AAFCO) framework, but pet supplements do not, and CVM states it will generally allow marketing of companion animal supplements if they meet specific criteria: fulfills a nutritional need, appropriate dosing, no disease claims, accurate labeling, and no safety risks. AAFCO currently regulates labeling only for “food type” supplements, while several states have enacted additional “remedy laws” to oversee non food pet supplements, leaving overall regulation fragmented and less standardized than for human supplements.8 Table 1: Resources for pet supplements National Institutes of Health Office of Dietary Supplements https://ods.od.nih.gov/ U.S. Food & Drug Administration (FDA) Center for Veterinary Medicine (CVM) https://www.fda.gov/animal-veterinary Association of American Feed Control Officials (AAFCO) https://www.aafco.org/ U.S. Pharmacopeia (USP) https://www.usp.org/ National Animal Supplement Council https://www.nasc.cc/ Consumer Lab https://www.consumerlab.com/ Herb List App NIH National Center for Complementary and Integrative Health https://www.nccih.nih.gov/health/herblist-app NatMed Pro https://naturalmedicines-therapeuticresearch-com.us1.proxy.openathens.net/Home/ND Medline Plus Herbs and Supplements Database https://medlineplus.gov/druginfo/herb_All.html#A Plumb’s (with subscription-database for drugs and supplements) https://app.plumbs.com/ Veterinary Information Network (VIN) (with membership) Drug Formularies, Drug labels, Client information Sheets, MSDS/SDS www.vin.com Choosing supplements that have earned the National Animal Supplement Council (NASC) Quality Seal ensures the product has met standards of safety and transparency. The NASC Quality Seal signifies a company has passed a rigorous third-party audit and maintains ongoing compliance with quality control measures. These include having written standard operating procedures for production, an adverse event reporting system, accurate and compliant labeling, and participation in random product testing to verify ingredient content claims. Unlike other generic pet supplements, those bearing the NASC seal come from manufacturers committed to product improvement and maintaining consumer trust. This seal represents a reliable marker for veterinarians and pet owners seeking safe animal health supplement products.9 Concerns, discrepancies, and questions Concerns raised in pet supplements include ingredient purity, potency, efficacy, and consistency, as well as the potential presence of contaminants, adulterants, or undeclared substances. Independent analyses have repeatedly demonstrated discrepancies between labeled and actual ingredient concentrations in both human and veterinary supplements, raising questions about product reliability and the potential for therapeutic failure.10 Unintended adverse effects, as well as lack of product efficacy, are a real concern, especially when combined with multiple other supplements or a pet’s prescribed medications. For veterinarians, understanding these issues is essential not only for evaluating products but also for counseling clients who may assume that all supplements are subject to the same scrutiny as prescription medications. Another concern is the low level of scientific evidence supporting—or failing to support—specific supplement ingredients. Certain compounds, such as omega-3 fatty acids and probiotics, have been studied in controlled trials with varying degrees of rigor, but many other supplement ingredients lack robust data directly in companion animal species. Extrapolation from human or laboratory animal research is common but may not always be appropriate given species-specific differences in metabolism, bioavailability, and physiologic responses. Even when evidence exists, it may be limited by small sample sizes, short study durations, inconsistent outcome measures, or methodological study weaknesses that complicate interpretation. Tips for assessing and utilizing pet supplements Identify reputable brands Check the company history, reputation. Is this a veterinary-exclusive brand (sold through veterinarians) or marketed directly to pet owners? Is it a pharmaceutical company making the supplement? Often, these companies will follow FDA drug standards for their pet supplements in process and marketing. Does the product carry the NASC seal? What level of support is available through consumer care, adverse event reporting, or veterinary support (education, flyers, etc.). Assess product ingredients Actives–What is the dose and form? Does the supplement use “proprietary blends”? If so, exact dosing will be unknown. Does the product use branded or patented ingredients (these may have clinical evidence studies by the manufacturer)? Inactives–What else is present in the product (flavorings, carriers, preservatives, binders, flow agents, stabilizers, etc.). Are any of these inactives problematic for this patient? Review/confirm clinical evidence for actives Published dosing (Does it match product content? Can you determine that from the product label or marketing?) Evaluate quality of study (Ise hierarchy of evidence11) Is it a single active study (preferred) vs. a combination product study? Does the combination of ingredients in this supplement match the product exactly you are evaluating? Develop a supplement protocol for common conditions For each disease, select trusted products and combinations. Compile data/references for each active ingredient and combination supplement products. Build a database over time and keep information available for pet owners, written in client-friendly wording similar to prescription drug handouts. Develop a protocol for each patient to collect as part of the patient history the complete diet (pet foods and all treats), supplements given (brand, dose, frequency), and medications (drug, dose, frequency). An additional challenge is the heterogeneity of supplement formulation combinations, which makes it difficult to generalize findings across products; a positive study on one manufacturer’s probiotic strain, for example, does not guarantee similar effects from another product containing the same genus species but a different strain, concentration, additional ingredients, or alternative delivery system. This variability makes it difficult for general practitioners with limited time to assess products, even when reviewing the available literature. Transparency on ingredient sourcing, manufacturing practices, and quality assurance protocols may also be lacking, which can make it difficult or impossible to reasonably evaluate products. Taking a proactive approach Despite these challenges, it is important to recognize supplements can play a meaningful role in patient care when selected carefully and used judiciously. Supplements can enhance patient care, address individual patients’ nutritional needs, or provide multimodal treatment that reduces reliance on traditional therapeutics for certain disease conditions. Using fewer prescription medications may reduce the risk of adverse drug effects. Clients are highly motivated to pursue more integrative or preventive health strategies, and supplements often serve as an accessible entry point for these conversations. Engaging proactively with clients about supplements can help guide them toward products with credible evidence, transparent labeling, and reputable manufacturing standards. This can reduce the risk of ineffective or unsafe supplement use, as well as conserve resources for proper medical care. Guidance on supplement use is particularly important for patients with chronic conditions, such as osteoarthritis, dermatologic disease, gastrointestinal disorders, or cognitive decline, where supplements may complement conventional therapies. Providing pet owners with clear communication about expected benefits, realistic timelines for positive responses, and potential interactions with other medications or supplements is essential. Equally important in the supplement conversation is the recognition that “natural” does not equate to harmless. Botanicals and other bioactive compounds can exert pharmacologic effects, interact with drugs, or cause adverse reactions, especially when used in combinations. It is essential for practitioners to document a thorough patient’s medical and nutritional history, including all foods, supplements, treats, and over-the-counter products administered to the pet. This is a critical component of safe and effective clinical decision-making. Documentation of supplement recommendations as part of the total treatment plan can ensure that these recommendations are followed, and treatment plans can be adjusted as needed as the pet’s health changes over time. Advocating for your patients Ultimately, the growing prevalence of supplement use in companion animals reflects both an opportunity and a responsibility for the veterinary profession. Supplements have the potential to enhance patient well-being when use is grounded in sound science and integrated thoughtfully into individualized care plans. However, because supplements have variable quality and inconsistent evidence of efficacy or even safety, veterinarians are called to remain vigilant, informed, and engaged in what pet owners choose to add to their pets’ daily routine. Maintaining open communication will help ensure that pet supplements are used safely and effectively to support their dog’s or cat’s health. Laura B. Gaylord, DVM, DACVIM (Nutrition), is an independent consultant and the owner/founder of Whole Pet Provisions, PLLC, a nutrition consulting company established in 2016, which offers veterinary nutrition consulting to pet owners, veterinarians, the pet food industry, and pet supplement companies. Dr. Gaylord offers homemade diet recipe formulation and commercial diet consultations through her business for pet parents and their veterinary team. References Zhao L, Zhang Y, Liu J, et al. Trends in dietary supplement use among U.S. adults between 2011 and 2023. Eur J Nutr 2025;64:304. Analytics U. Pet Supplements Market Size, Share, Trends & Growth Forecast, 2025;212. Cleaver L. U.S. pet supplement market surpasses $2.7B, driven by health and wellness trends: PETFOOD Industry. Bruno R. Use of real-world data as pivotal evidence in veterinary regulatory applications. Front Vet Sci 2025;12:1588068. Carson A, Kresnye C, Rai T, et al. Response of pet owners to Whistle FIT(®) activity monitor digital alerts of increased pruritic activity in their dogs: a retrospective observational study. Front Vet Sci 2023;10:1123266. Thonen-Fleck C, Sharon KP, Enomoto M, et al. Physical Activity Monitors in Companion Animal Chronic Pain Research-A Review Focused on Osteoarthritis Pain. Animals (Basel) 2025;15. Supplements NIoHOoD. Dietary Supplement Health and Education Act of 1994 Public Law 103-417 103rd Congress. 1994; https://ods.od.nih.gov/About/DSHEA_Wording.aspx. Accessed 1/4/2026. Finno CJ. Veterinary Pet Supplements and Nutraceuticals. Nutr Today 2020;55:97–101. (NASC) NASC. https://www.nasc.cc/. Accessed 11/13/2025, 2025. Starr RR. Too little, too late: ineffective regulation of dietary supplements in the United States. Am J Public Health 2015;105:478–485. Wallace SS, Barak G, Truong G, et al. Hierarchy of Evidence Within the Medical Literature. Hosp Pediatr 2022;12:745–750.
