There could be a rather large cat fight on the horizon. Nestle Purina PetCare is suing rival Blue Buffalo alleging the company is lying about the natural ingredients in its pet food.

St. Louis-based Purina filed a lawsuit [PDF] in federal court Tuesday accusing Blue Buffalo of false advertising, disparagement and unjust enrichment.

Purina, the maker of brands like Beneful and Friskies, claims that Blue Buffalo’s ads stating its products contain “only the finest natural ingredients” and “no chicken or poultry byproduct meals” are false and violate the Federal Lanham Act.

“This is not an action we take lightly,” Steven Crimmins, Vice President and Chief Marketing Officer of Nestlé Purina, says in a statement. “We believe consumers deserve honesty when it comes to the ingredients in the food they choose to feed their pets.”

A rep for Blue Buffalo tells Consumerist that the company will have an official statement sometime this afternoon. We will update this post when we receive it.

Purina alleges that testing conducted by an independent lab revealed that several of Blue Buffalo’s top-selling Life Protection products contain significant percentages of poultry by-product meal. The complaint claims the testing also found Blue Buffalo LifeSourceBits contain poultry by-products meal and corn.

Additionally, Purina alleges that products advertised as grain-free were found to contain rice hulls.

According to the complaint, Blue Buffalo spent approximately $50 million last year to promote its claims that its ingredients were superior to competitors.

“With tens of millions of dollars in advertising and a small army of in-store marketers, BlueBuffalo has built a brand targeted at ingredient-conscious pet owners,” the complaint states. “It has become increasingly clear, however, that Blue Buffalo’s brand is built instead on a platform of dishonesty and deception.”

This isn’t Blue Buffalo’s first issue regarding its product advertising. In March, the National Advertising Division (NAD) of the Council of Better Business Bureaus found the company’s True BLUE Test to be falsely disparaging to competing pet food companies.

In that case, Hill’s Pet Nutrition, Inc., the manufacturer of Hill’s Science Diet, challenged the advertisements. After its review, NAD recommended that Blue Buffalo change its claims.

Purina Sues Blue Buffalo For False Advertising and Disparagement [Purina]

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