FDA warns Quest cat food lots may cause severe thiamine deficiency

The FDA has escalated its concerns over Steve’s Real Food’s Quest cat diets, warning that eight tested lots contain extremely low or no thiamine and could cause serious illness or death in cats. In a March 13, 2026, advisory, the agency said it had received multiple consumer complaints involving severe thiamine deficiency and had recommended that Go Raw LLC, which markets Quest Cat Food under the Steve’s Real Food name, recall all eight lots. FDA said only three lots had been formally recalled as of that notice. (fda.gov)

The company’s public actions started earlier and were narrower. On February 17, 2026, Go Raw announced a voluntary recall of one lot of Quest Cat Food Chicken Recipe Freeze Dried Nuggets after a veterinarian-submitted sample tested low in thiamine; the company said one cat illness had been confirmed and that the cat recovered after treatment. Then, on February 26, the company expanded the recall to include two frozen chicken lots and said it would stop sale of all Quest products at retail until the thiamine issue was addressed. (fda.gov)

What changed with the FDA advisory is the scope and the tone. The agency said all eight lots it tested were far below the AAFCO Cat Food Nutrient Profile minimum of 5.6 mg/kg thiamine on a dry matter basis. FDA listed the three already recalled chicken products, but also identified five additional lots that had not been formally recalled at the time of the advisory: freeze-dried pork, beef, white fish, chicken, and another pork lot. For the two frozen chicken lots, FDA reported no detectable thiamine. FDA also said the firm had not provided evidence showing the remaining affected lots had been removed from the marketplace and that customers had been adequately notified. (fda.gov)

That matters because thiamine deficiency in cats can move from vague gastrointestinal signs to neurologic crisis. FDA says early signs may include decreased appetite and vomiting, while advanced cases can involve cervical ventroflexion, weakness, wobbly gait, circling, falling, seizures, and death if untreated. The agency noted some cats may show signs in as little as one week, though others may take months. Merck Veterinary Manual similarly describes thiamine deficiency as most common in cats among companion animals and says inadequately formulated commercial diets are a recognized cause. (fda.gov)

Industry coverage has largely echoed the regulatory concern rather than adding much public expert debate. PetfoodIndustry reported that the initial recall was triggered after illness in a cat eating the product, with the treating veterinarian’s testing showing thiamine below required feline levels. dvm360 highlighted the gap between the FDA-tested lots and the smaller number of lots formally recalled, reinforcing the practical challenge for clinicians and pet parents trying to determine exposure risk. (petfoodindustry.com)

Why it matters: For veterinary professionals, this is a reminder that nutritional deficiency recalls can present like neurology, GI disease, or vague systemic illness before anyone thinks “diet.” Cats on boutique, raw, frozen, or freeze-dried diets may arrive with anorexia, weight loss, vomiting, weakness, vestibular signs, or seizures, and diet history becomes central. Because FDA says Quest products were sold online and distributed nationwide, and because some affected lots were not formally recalled at the time of the warning, clinics may need to proactively ask pet parents about brand, formula, lot code, and feeding duration. Early recognition matters: FDA says signs are typically reversible when caught early and the diet is changed, and Merck notes diagnosis is often supported by response to thiamine administration. (fda.gov)

The broader lesson is about verification of nutritional adequacy claims. FDA pointedly noted that the products were labeled as complete diets meeting AAFCO nutrient profiles, yet agency testing found thiamine levels far below that standard. For practices fielding questions from pet parents, this case is likely to sharpen scrutiny of specialty cat diets that market themselves as complete and balanced without the depth of quality-control transparency many clinicians would like to see. That doesn’t settle the wider raw-versus-conventional debate on its own, but it does reinforce a narrower point: when a diet is the sole source of nutrition, micronutrient consistency is non-negotiable. (fda.gov)

What to watch: The next signals will be whether Go Raw formally recalls the remaining five FDA-identified lots, whether FDA escalates beyond an advisory if product remains in commerce, and whether more case reports emerge as veterinarians and pet parents connect neurologic or GI signs to prior Quest exposure. (fda.gov)