Under the Pure Pet Food Act of 1969 (HSC Chapter 10), a "pet food ingredient or a processed pet food shall be deemed to be adulterated" on multiple grounds (§113090). It is adulterated "(a) If it bears or contains any poisonous or deleterious substance that may render it injurious to health" and, separately, "(b) If it bears or contains any added poisonous or deleterious substance, any food additive, any pesticide chemical, or any color additive that is unsafe within the meaning of the Federal Food, Drug and Cosmetic Act, or Part 5 (commencing with Section 109875), or Division 7 (commencing with Section 12501) of the Food and Agricultural Code" (§113090).
Sanitary conditions matter: a product is adulterated "(d) If it has been produced, prepared, packed or held under insanitary conditions whereby it may have become contaminated with filth, or whereby it may have been rendered diseased, unwholesome or injurious to health" (§113090). Economic adulteration is also covered: "(f) If any valuable constituent has been in whole or in part omitted or abstracted therefrom." "(g) If any substance has been substituted wholly or in part therefor." "(h) If damage or inferiority has been concealed in any manner." and "(i) If any substance has been added thereto or mixed or packed therewith so as to increase its bulk or weight or reduce its quality or strength or make it appear better or of greater value than it is" (§113090).
A 2025 amendment (effective January 1, 2026) carved out industrial-hemp CBD: "A processed pet food is not adulterated because it includes cannabidiol (CBD) derived from industrial hemp, as defined in Section 11018.5, if the industrial hemp product does not contain any other cannabinoid or synthetic cannabinoid and meets the requirements established in Chapter 9 (commencing with Section 111920) of Part 5." The statute adds that "The sale of processed pet food that includes CBD derived from industrial hemp shall not be restricted or prohibited based solely on the inclusion of CBD" (§113091).