Researching the Research on Canine Supplements
Dr. Leilani Alvarez shares tips for evaluating the studies.
We know that canine performance competitors are very discerning about what they give their pets, and many do their homework to research the best options available. With so much information available, it is tough to sift through all the choices. We asked our favorite authority to share her thoughts.
Dr. Leilani Alvarez, DVM, DACVSMR, is Senior Veterinarian and Director of Integrative and Rehabilitative Medicine at Schwarzman Animal Medical Center in New York City. She has conducted USDAA Facebook Live interviews and article interviews with us over the years. 
Dr. Alvarez recommends keeping these four points in mind when researching supplements:
- Does the supplement come from a well-established company (one that’s been in business for at least 10 years)?
- Has the product been tested and verified by a third-party laboratory?
- Are there published safety and efficacy studies related to the product?
- Have studies been done to demonstrate appropriate dose and frequency and that the products are bioavailable?
However, even if the product comes from a well-established company, Dr. Alvarez said she doesn’t rely only on information coming from that company. Instead, she focuses on choosing products where third-party testing is obvious on the label, such as Good Manufacturing Practice (GMP) and National Animal Supplement Council (NASC) labels.
More of her tips follow in the Q&A below.
Q: Where can dog owners find research studies on supplements? Are there best sources to monitor?
A: I like PubMed and Google Scholar. This ensures the study is published and not just a company "white paper."
Q: When reviewing studies (often in peer-reviewed journals), what is the best way to sort out/analyze the data? For example, summaries, who conducted the study, etc.?
A: When critically evaluating published peer-reviewed studies, it is important to consider (1) The institution: Do we trust this institution? For example, I trust a U.S. veterinary school publication far more than one coming out of China or other countries with less rigorous academic standards; (2) The authors: Are they reputable and recognized in their field? (3) Is the study randomized (i.e., does it use random selection or sampling)? (4) Is the study blinded (a type of study in which the patients or the patients and their doctors do not know which drug or treatment is being given)? (5) Is there a control group? If factors 3, 4 and 5 are not present, there is a high risk of bias in the study.
Also, are the conclusions appropriate for the actual results obtained? Many authors draw conclusions that are not supported by the results. A reputable journal with rigorous peer review will address this, but there are so many journal publications these days that it's hard to give solid criteria here. The highly recognized and reputable journals in vet medicine include Journal of the American Veterinary Medical Association (JAVMA), Veterinary Surgery, American Journal of Veterinary Research (AJVR), Journal of Veterinary Internal Medicine (JVIM), Journal of the American Animal Hospital Association (JAAHA), and Veterinary and Comparative Orthopaedics and Traumatology (VCOT).
Q: When researching supplements, should we look for something that says it is “clinically-proven” or “scientifically proven,” and is this important?
A: Those terms are not regulated and often used for marketing purposes by a company. I would verify that a prospective study actually exists and was published. The study should be on THEIR product (they often quote studies from other products), on live dogs (prospective study), suffering from a naturally occurring disease (not experimentally induced).
The easiest and simplest thing consumers can do to choose quality veterinary supplements is to ensure they have a NASC label.
Q: Are there any new studies you can mention specifically to help our readers select supplements or dog food?
A: The latest study on dog and cat joint supplements was a systematic review and meta-analysis (highest level of evidence) published last year (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9499673/) which concluded that glucosamine and chondroitin should not be recommended for the treatment of feline and canine osteoarthritis.
Q: Another recent study our readers have seen is from Frontiers in Veterinary Science: Study of the effectiveness of glucosamine and chondroitin sulfate, marine based fatty acid compounds (PCSO-524 and EAB-277) and carprofen for the treatment of dogs with hip osteoarthritis. Does it meet your criteria?
A: Yes, it does. This is a well-conducted study. While its origin in Thailand might raise suspicion, Duncan Lascelles led the study and is a highly respected and reputable researcher. Therefore, I trust these results and conclusions.
About Leilani Alvarez DVM, DACVSMR
Dr. Leilani Alvarez is the Director of Integrative and Rehabilitative Medicine at the Schwarzman Animal Medical Center in New York City. She is a board-certified diplomate of the American College of Veterinary Sports Medicine and Rehabilitation and certified in veterinary acupuncture (CVA), canine rehabilitation (CCRT) and advanced Chinese herbal medicine (CAVCHM). Dr. Alvarez graduated with high honors from the University of Georgia College of Veterinary Medicine in 2002 and completed her internship and residency at the Animal Medical Center. She has been practicing rehabilitation and integrative veterinary medicine for over 15 years and leads one of few traditional residency programs in canine sports medicine and rehabilitation. In addition to running a busy rehabilitation practice, Dr. Alvarez is a frequent lecturer at national and international conferences, teaches interns and residents and has published peer review articles and book chapters. She is also fluent in Spanish. Her research interests include geriatric medicine, joint supplements, muscle physiology and evidence-based medicine.