1A)  Well-designed studies investigating the mode of action of the supplement are needed to properly describe how they work to steer future research and regulatory action. Efficacy and safety studies in rodents do not always provide results that can be adapted to pets.

Well documented manufacturing processes which account for all impurities and residual solvents, raw materials, and processing aids are sometimes lacking, as this will shape the GMP production overall and remove hurdles at the regulatory stage.

 1B)  Species-specific research is a requirement for satisfying the increasingly strict regulatory environment. Comparisons to humans and rats do not account for differences in digestive systems, dietary needs, or metabolism. While a promising effect may be seen in humans this is only helpful in providing a direction for future animal studies.

1F) At least 1 study in target animals evaluating safety endpoints and at least 3 studies in target animals evaluating efficacy endpoints should be expected. Safety and efficacy studies can be combined. Study parameters need to be targeted to the claimed effect and consider any potential effects on organs, growth, and maintenance.

1H)  There is a desire to avoid studies in animals where the animals need to be terminated to collect samples. This means that indirect tests of biomarkers can make seeing a clear effect of the supplement difficult. Larger sample sizes are needed, and study directors may need to consider biopsies and/or the inclusion of more thorough parameters that can be obtained from blood, urine, digesta, and faeces, as relevant.

Second, there are few accredited GLP labs available to conduct appropriate studies in pets while regulators have been increasing their scrutiny over the quality of the studies that are submitted. Complete study protocols and confirmation with the labs about their accreditation and GLP compliance should be well established before commencing any study.

3A) Ingredients for inclusion in pet supplements in the EU are regulated as feed materials (if they primarily provide nutrition) or as feed additives. Substances making performance or production claims may be zootechnical feed additives, requiring authorisation by EFSA before going to market (1). However, in the U.S. there is no formal pre-market approval system for pet supplements, which may be marketed as feed in the U.S. if they provide a nutritional effect. Providing a “zootechnical” effect would have the supplement regulated as a drug. Ingredients used in feed-type supplements must be listed under a food additive regulation or exempted through a GRAS conclusion. In the past state feed regulators demanded that GRAS conclusions be notified to the FDA or proceed through an approval process with the Association of American Feed Control Officials (AAFCO). AAFCO provides standards and definitions widely implemented at a state-level; however, AAFCO is not a regulatory body, and thus enforcement is based on individual state law enforcement (2). Some pet supplement ingredients that do not fall within the FDA definition of “food” because of stated claims may not have been reviewed by FDA, but have been documented under the National Animal Supplement Council (NASC) certification program. The FDA uses regulatory discretion for NASC supplements provided certain criteria for facility inspection, adverse event reporting, and safety are met.

Overall, the biggest difference between the EU and U.S. when it comes to the regulation of pet supplements is that ingredients need pre-market approval in the EU, but in the U.S. regulation of pet supplements have multiple options depending on the ingredient and its function and some paths are reliant on post-market enforcement. Therefore, an ingredient easily used in pet supplements in the U.S. may face significant hurdles if the ingredients used in the supplement are not approved in the EU. To further complicate things, similar to reviews and implementation by states in the U.S., EU member states may also implement additional regulations (3). Therefore, companies wishing to market pet supplements in the U.S. and EU will need to potentially navigate 50 different state laws, and regulations across 27 member states.

3B) Claims suggesting a supplement product or ingredient can “diagnose, treat, cure, mitigate, or prevent a disease or abnormal condition” represent the highest regulatory risk, as that puts a supplement squarely in the drug category (4, 5). This would include claims such as “prevents arthritis” or “cures anxiety” to name a few. However, nutritional or structure/function claims are the most likely to be accepted if there is sufficient scientific backing. One ingredient with strong scientific evidence are omega-3 fatty acids, which can support healthy skin and coat, and joint health in pets (6, 7, 8).

3C) Oversight will likely become stricter. There is a push from the U.S. government to mandate GRAS notifications which would require many ingredients that are currently on the market to be reviewed by the FDA. There is also growing demand from customers that pet food and supplements receive the same level of oversight as human food, partly owing to how pet owners consider their pets as family. In the EU, EFSA will be paying close attention to claims and efficacy studies used to support pet supplement claims, making study design and obtaining acceptable results more challenging.

4B) The biggest change that could be made to improve consumer trust in pet supplements is an increased regulatory oversight by requiring more robust analytical testing. It has been well reported that dietary supplements intended for human consumption in the U.S. have been reported to be tainted, or do not contain the ingredients declared on the label (9, 10). Considering that dietary supplements receive some oversight by the FDA and the Dietary Supplement Health and Education Act (DSHEA), and pet supplements in the U.S. receive less regulatory oversight in comparison, it is safe to assume these same concerns for adulteration and missing ingredients would also extend to pet supplements. Considering the increase in pet humanization, it is becoming even more important for consumers that the pet supplements they are purchasing do not cause harm, and are truthful in their ingredient list (11, 12). By requiring analytical testing from authorized third-party labs, and publication of the resulting Certificates of Analysis (CoA) on the supplement companies’ website, consumers can be assured exactly what they are putting in their pet’s bodies. This proposed requirement for analytical testing and declaration should also extend to dietary supplements for humans to improve trust in the industry.

4A) Transparent relationships between manufacturers, regulatory officials, and consumers is key. Additionally, sufficient protections for innovations will be needed. It is already happening in the EU that when a feed additive application is approved, the data contained therein cannot be used by another applicant for 10 years. Public consultations and provision of data will engage customers and open trust, especially when a clear narrative is provided to explain the data in terms of how it supports safety and efficacy.