Dog Aging Project finds supplements are common in U.S. dogs

CURRENT FULL VERSION: Half of dogs in one of the country’s largest canine health datasets are getting supplements, according to a new Dog Aging Project analysis that puts numbers behind a trend many clinicians already see in exam rooms. Using enrollment survey data from 40,367 U.S. dogs collected from January 1, 2020, through December 31, 2022, the researchers found that 20,993 dogs, or 52%, were reported to receive supplements. Among supplement users, omega-3 fatty acids and joint supplements were the leading categories, each used in more than half of supplemented dogs. The study was published online in November 2025 in the American Journal of Veterinary Research, with print publication dated February 1, 2026. (pubmed.ncbi.nlm.nih.gov)

The findings come out of the Dog Aging Project, a large, longitudinal U.S. research effort designed to study how genetics, environment, and lifestyle shape healthy aging in companion dogs. As of August 2023, the project reported more than 45,000 enrolled dogs, with survey data updated annually and supplemented, when available, by veterinary medical records and biospecimen collection in subcohorts. That scale has already supported earlier nutrition and epidemiology work, including prior Dog Aging Project studies on joint supplement use and broader diet patterns. (content.dogagingproject.org)

In the new supplement analysis, the authors set out to describe what dogs are getting and whether use tracks with specific health conditions. Their topline conclusion: supplement administration is common, and dog-level factors appear to matter more than pet parent demographics. The abstract highlights especially frequent use among dogs with orthopedic conditions, while the related AVMA podcast summary adds a life-stage pattern that may be clinically intuitive: joint supplement use rises with age, probiotics peak earlier in life, and omega-3 use remains comparatively steady across age groups. The podcast description also points to a largely reactive pattern, with dogs perceived as less healthy more likely to receive supplements. That interpretation is consistent with earlier Dog Aging Project work showing supplement and diet choices often cluster with dog characteristics such as age, size, activity, health status, and life stage. (pubmed.ncbi.nlm.nih.gov)

The broader evidence picture is mixed, which helps explain why this paper is likely to resonate with practicing veterinarians. In a 2022 systematic review and meta-analysis of enriched therapeutic diets and nutraceuticals for canine and feline osteoarthritis, investigators concluded that chondroitin-glucosamine products showed strong evidence of non-effect and differed significantly in efficacy from better-performing categories. The 2022 AAHA Pain Management Guidelines, meanwhile, place omega-3 supplementation among tier 1 nondrug options for chronic musculoskeletal pain, while noting less support for non–omega-3 nutritional supplements. In other words, common use does not necessarily track with strong evidence. (pmc.ncbi.nlm.nih.gov)

That gap between popularity and proof is part of the reason industry and clinical interest remain high. The Veterinary Vertex episode framing the paper says the researchers discussed “bold marketing claims,” strain-specific realities for probiotics, and practical scripts for talking with clients about evidence quality. While the episode description is not a peer-reviewed source, it reflects the kind of counseling challenge many veterinary teams face: pet parents often arrive having already purchased a supplement, and the conversation has to move quickly from marketing language to expected benefit, dose, product quality, and measurable outcomes. (podcasts.apple.com)

Why it matters: For veterinary professionals, this study is a reminder that supplement use is mainstream enough to deserve the same routine history-taking as diet, treats, and preventives. It also reinforces that nutrition and supplement studies in pet dogs can be confounded by the kinds of dogs receiving those products. Earlier Dog Aging Project work on dietary choices found that dog demographic factors, including size, neuter status, activity level, and life stage, were often more strongly associated with feeding patterns than owner factors. That makes careful interpretation essential when pet parents attribute a dog’s health status to a supplement or feeding approach. Clinically, the practical implication is straightforward: ask specifically what the dog is getting, why it was started, what outcome the pet parent expects, and whether there has been an objective response. (pmc.ncbi.nlm.nih.gov)

Regulatory context also matters. FDA says products intended for animals may be regulated differently depending on intended use, and items intended to diagnose, cure, mitigate, treat, or prevent disease fall under the drug definition. But many products sold into the pet market are positioned more like foods or supplements and do not undergo the same approval process as FDA-approved animal drugs. For clinicians, that means product quality, label accuracy, and efficacy data can vary substantially, making veterinary guidance especially valuable when pet parents are navigating over-the-counter choices. (fda.gov)

The study also lands in a broader conversation about veterinary data infrastructure. In a separate Veterinary Vertex discussion on a One Health integrated companion animal health surveillance system, AVMA highlighted the challenge that relevant human, animal, and environmental data sources often exist in silos and are not readily compatible. The goal of better integration, as described in that episode, is to support more timely surveillance and risk mitigation by bringing diverse datasets together in ways that allow more realistic analyses of health outcomes. While that conversation was not about supplements specifically, it helps frame why large companion-animal datasets such as the Dog Aging Project matter beyond any single paper: they are part of a larger push to make pet health information more usable for both clinical insight and population-level surveillance.

What to watch: The immediate next step is likely not a regulatory change, but a shift in how clinics document and discuss supplement use, especially in senior dogs and dogs with orthopedic disease. Longer term, the Dog Aging Project’s growing dataset should allow for more targeted analyses by condition, life stage, and diet pattern, which could help clarify where supplement use reflects evidence-based care, where it reflects hopeful experimentation, and where veterinary teams may need better tools for counseling pet parents. And if broader One Health surveillance efforts gain traction, the value of consistently captured companion-animal data—including routine supplement exposure—could extend well beyond individual appointments. (pubmed.ncbi.nlm.nih.gov)