Expert Report

Safety of Dietary Supplements for Horses, Dogs, and Cats (2008)

Each report is produced by a committee of experts selected by the Academy to address a particular statement of task and is subject to a rigorous, independent peer review; while the reports represent views of the committee, they also are endorsed by the Academy. Learn more on our expert consensus reports.

Growing numbers of pet owners are giving their pets dietary supplements in hopes of supporting their health. This increased use of animal dietary supplements has raised concerns regarding the safety of specific supplements and the guidelines for determining safety of dietary supplements for horses, dogs, and cats. At the request of the Food and Drug Administration (FDA), the Natural Research Council convened a committee of experts to assess the safety of supplements in general and to review three specific supplements (lutein, evening primrose oil, and garlic) offered for horses, dogs, and cats. This report concluded that because of inadequate data, an upper limit of safe use of lutein, evening primrose oil, and garlic could not be determined but could cite historical safe intakes (HIS) and estimate presumed safe intakes (PSI) based on available research findings. The report also stresses that clear and precise regulations need to be established.

Key Messages

  • Based on the three specific animal dietary supplements studied, it is clear that safety of the same supplements in humans does not guarantee safety in animals.
  • Because of the limited amount of data with target animals, research findings in other species provide important safety signals.
  • The absence of laws and regulations that specifically address animal dietary supplements causes considerable confusion to the industry and the public.
  • The committee could not identify data on lutein, evening primrose oil, or garlic that would allow for a quantitative upper limit of safety to be clearly defined (e.g., NOAEL or SUL).
  • The committee ranked the suitability of assessing acceptable and relevant data based on the broad seven-class scale, with class 1 providing the highest degree of confidence.
  • There are insufficient safety data for these supplements of a quality normally required for animal drugs and food additives.