Ninth Circuit Upholds Class Certification in Cosequin False Advertising Case

The U.S. Court of Appeals for the Ninth Circuit has affirmed a district court order certifying a class of California consumers in Lytle v. Nutramax Laboratories, Inc., a case challenging the marketing of Cosequin, a popular joint supplement for dogs.

The plaintiffs are dog owners who purchased Cosequin products based on labeling that promoted joint health benefits. They allege that those claims were misleading and that scientific evidence does not support the promised benefits. The lawsuit was brought under the California Consumers Legal Remedies Act and focuses on whether consumers paid for something they reasonably believed would help their dogs, but did not.

At this stage, the question before the Ninth Circuit was not whether the claims were true or false. Instead, the issue was whether the case could proceed as a class action. Nutramax argued that it could not, challenging both how damages would be measured and whether reliance on the alleged misrepresentations could be shown on a class-wide basis.

The Ninth Circuit rejected those arguments and affirmed class certification.

One issue centered on damages. The plaintiffs’ expert proposed a damages model using a survey-based approach designed to measure how much consumers paid for the alleged misrepresentations. Nutramax argued that the model could not support class certification because it had not yet been fully executed. The court disagreed, explaining that there is no general requirement that a damages model be completed before certification. What matters at this stage is whether the model is reliable and capable of showing damages using common proof. The court found that standard was met.

Nutramax also challenged whether consumers’ reliance on the product labeling could be proven across the class. Under California law, if a misrepresentation is material and made uniformly to consumers, courts may presume reliance. The Ninth Circuit agreed with the district court that the labeling statements at issue were material and that Nutramax had not rebutted the presumption of class-wide reliance.

Together, these rulings reinforce an important point in consumer cases. Companies cannot avoid class actions simply by arguing that damages models are incomplete at the certification stage or by asserting that individual consumers may have purchased products for different reasons. Where alleged misrepresentations are consistent and material, class treatment may be appropriate.

For consumers, the decision means the case will move forward on a class-wide basis, allowing dog owners to pursue their claims together. More broadly, the ruling underscores that product labels matter, especially when they make claims consumers rely on when deciding what to buy for themselves or, in this case, their pets.

The Ninth Circuit’s decision keeps the focus where it belongs: on whether marketing claims are accurate and whether consumers were given clear, truthful information when making purchasing decisions.