KetoNatural v. Hill's Pet Nutrition — Lanham Act False Advertising Lawsuit Over Grain-Free DCM Claims
KetoNatural Pet Foods, a manufacturer and seller of grain-free pet food, treats and supplement products, filed a $2.6 billion Lanham Act false advertising lawsuit against Hill's Pet Nutrition (a Colgate-Palmolive subsidiary), the Morris Animal Foundation, the Mark Morris Institute, and five veterinary researchers — Drs. Lisa Freeman, Joshua Stern, Darcy Adin, Ryan Fries, and John Rush — in February 2024, alleging that Hill's and the associated researchers "weaponized" the FDA's DCM reporting system to suppress the grain-free pet food market segment.
Procedural History
- February 2024: KetoNatural filed the lawsuit in the United States District Court for the District of Kansas (case 2:24-cv-02144), on behalf of itself and a putative class of pet food manufacturers and retailers.
- June-July 2024: KetoNatural voluntarily dismissed all defendants other than Hill's, but maintained the civil conspiracy claim under Kansas state law.
- June 2024: Hill's moved to dismiss the complaint under Rule 12(b)(6) for failure to state a claim.
- District Court: Dismissed the complaint with prejudice, finding that KetoNatural failed to plausibly allege actionable Lanham Act false advertising.
- November 2025: The United States Court of Appeals for the Tenth Circuit affirmed the dismissal in its published opinion (case 24-3173 or related).
The Two Claims Asserted
- False advertising under the Lanham Act (15 U.S.C. § 1125(a)(1)(B)) — alleging that Hill's marketing statements falsely tied grain-free diets to DCM.
- Civil conspiracy under Kansas state law — alleging coordinated action between Hill's and the five veterinarian defendants / two foundation defendants.
Tenth Circuit Holding
The appellate panel held that:
- None of the challenged Hill's statements were literally false on their face or actionable as Lanham Act establishment claims. Specifically, statements characterizing the FDA case reports ("Research has now shown that these diets ... are commonly grain-free commercial dry diets that contain pulses and, to a lesser extent, potatoes or sweet potatoes") and "Many have linked diet-associated DCM with grain-free diets" were characterisations of the FDA investigation record, not actionable establishment claims.
- The third-party Veterinarian defendants' statements were held to be non-actionable statements about a scientific issue, not commercial advertising or promotion by Hill's. As the court put it, these are "first-party statements by the scientists themselves, made in their own names, on scientific topics".
- Hill's statements about its own "prescription-only" market position ("#1 Vet-Recommended Brand") were commercial speech but did not constitute false advertising — they were not literally false.
- The civil conspiracy claim failed because the underlying Lanham Act claim failed and the alleged conspiracy was based on the same non-actionable conduct.
Significance
The case crystallises the post-2022 causality dispute about grain-free diets and canine DCM:
- Hill's side (and the peer-reviewed research, see companion topic
FDA_DCM_post_closure_science_2023_2025): the diet-DCM link (particularly legumes/pulses) is supported by echo and ECG studies. - KetoNatural side: the FDA's 2022 closure statement ("insufficient data for causal relationship") and the absence of a definitive mechanistic study mean that commercial statements about the link are not literally true, are commercially damaging, and may constitute false advertising.
The Tenth Circuit's affirmance of dismissal is a procedural win for Hill's (and the researchers) — it does not adjudicate the underlying scientific question. The diet-DCM link remains an active area of peer-reviewed research (the November 2025 Veterinary Sciences narrative review continues to support the link) and ongoing industry/policy debate.
Companion Lawsuit — Blue Buffalo (April 2026)
A separate lawsuit filed in April 2026 against Blue Buffalo alleges the company's grain-free dog food contributed to a pet's DCM. The case continues a wave of litigation targeting pet food makers over formulation choices and marketing claims tied to DCM concerns — including the Hill's and veterinarian defendants allegedly "manipulating" the FDA into examining grain-free diets' risk.
Source
pdf-raw/dcm-lawsuits/keto-natural-hills-scientific-answer-1.pdf (Tenth Circuit published opinion, downloaded from courthousenews.com, 2026-07-21). Industry-side timeline and analysis cross-referenced with North Point Pets narrative on Grain-Free Dog Food and Heart Disease (April 2026).
For the underlying FDA 2018-2022 investigation, see companion topics FDA_DCM_investigation_timeline_2014_2024 and FDA_DCM_investigation_closure_2022_dec. For the post-closure peer-reviewed science, see companion topic FDA_DCM_post_closure_science_2023_2025.