The Story About Supplements for Pets Like Cats

Niels C. Pedersen, DVM PhD

April 6, 2021

The use of supplements for dogs and cats has become increasingly more common, mirroring the increase in the use of supplements for people. I have also noticed that many owners of cats are using numerous supplements to augment treatment GS-441524 treatment for FIP. I feel strongly that these supplements have no efficacy and cost owners a tremendous amount of money. Some owners take it upon themselves to use supplements, but in some cases, they are used on recommendation of their veterinarians. There is also a heavier reliance on supplements in regions of the world where the state of veterinary care is lacking. In many cases they are “prescribed” to either prevent, retard, or reverse specific health conditions. In truth they are often used on the need to do something and that even if they do not work, they will not hurt. In some cases, there is a hint that a specific organ is “in need of some form of help.” A significant proportion of test panels done in even healthy animals will show one or more suspicious values, in particular involving blood, liver or kidney. Such values should not be used as a reason for prescribing or selling supplements. As a person who believes in the scientific method and clinical trials to establish safety and efficacy, I cannot in good conscience advise owners of to use untested over the counter supplements that claim to prevent, alleviate, or cure disease.

I am aware of the many testimonials that exist on the world wide web that attest to the efficacy of a vast array of products. However, there are also many articles from reputable sources that support my beliefs. I am quoting portions of such articles below.

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McKenzie B. The Top Ten Pet Supplements: Do They Work? Science Based Medicine, May 19, 2011. https://sciencebasedmedicine.org/the-top-ten-pet-supplements-do-they-work/.

An Embarrassment of Riches?

“Much has been written here about the dietary supplement business, a multibillion-dollar industry with powerful political connections, and about the woeful inadequacy of regulation which allows widespread marketing of supplements without a solid basis in science or scientific evidence. …………. . Of course, the marketing used to promote these supplements goes well beyond anything justified by real scientific evidence and is almost universally untrustworthy. Likewise, the testimonials and anecdotes about their effects, whether from patients, pet owners, veterinarians, or Nobel Laureates, are all just stories with almost no probative value. And since most good ideas in medicine ultimately fail to become real, effective clinical therapies, it is likely that many even of the more plausible of these products will turn out not to be useful or to have unknown risks. Without adequate supporting evidence and without effective quality control, regulation, and post-market surveillance, we can never be sure we are helping and not harming our patients by using them.”

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Finno CJ. Veterinary Pet Supplements and Nutraceuticals. Nutr Today. 2020;55(2):97-101. doi:10.1097/nt.0000000000000399. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7802882/.

“Claims of efficacy for many pet supplements and nutraceuticals are often based on subjective methods of assessment, including owner testimonials, which have not been rigorously tested in well-designed clinical trials and published in peer-reviewed journals, and should therefore be viewed with skepticism. While valuable for cross-species comparisons, results extrapolated from studies performed in humans or rodent models do not take into account the differing pharmacokinetics and pharmacodynamics among species. Additionally, many pet supplements and nutraceuticals are consumed orally, and oral bioavailability of drugs varies widely across species. Consumers should also be advised to be skeptical of marketing claims based on in vitro work. For example, many proposed benefits of pet joint supplements are based on in vitro work, which often relies on very high doses directly applied to cartilage explants or cultured chondrocytes.”

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Pet Nutrition Alliance. How are dietary supplements for animals regulated? https://petnutritionalliance.org/site/pnatool/how-are-dietary-supplements-for-animals-regulated/.

Answer:

• For animals, the U.S. Food and Drug Administration (FDA), Center for Veterinary Medicine  (CVM) regulates two classes of products: food and drugs. Depending on the intended use, an  animal dietary supplement is considered either a food or drug. There is no separate category  for “supplements” for animals.¹

• In the Dietary Supplement Health and Education Act (DSHEA) of 1994, the term “dietary  supplement” was defined but it did not specify if the definition applied to humans, animals, or  both. The main effect of DSHEA was to reclassify certain dietary ingredients from regulation as food additives, which require pre-market approval.²

• In 1996, CVM published a notice in the Federal Register to explain that DSHEA did not apply  to animal products.¹

• Simply, federal laws and regulations do not recognize a category of products for animals  called “dietary supplements.” Depending on the stated intended use, the product is either a  food or drug, regulated by the FDA. ¹

• Many owners purchase products intended for human use for their pets. It is important to know that manufacturers of human dietary supplements do not have to provide FDA with  evidence that their dietary supplements are effective or safe. However, they are not  permitted to (knowingly) market unsafe or ineffective products.²

• Once a human dietary supplement is marketed, the FDA has to prove that the product is not  safe in order to restrict its use or remove it from the market.²

• In contrast, before being allowed to market a drug, manufacturers must obtain FDA  approval by providing convincing evidence that it is both safe and effective.³

• Some supplements that are safe for humans can be toxic to dogs or cats.Therefore, it is imperative that pet owners consult with their veterinarians before giving a dietary  supplement to their pet.