Blue Buffalo, a pet food manufacturer preferred by many health-minded pet owners, is facing a lawsuit filed by Nestle's Purina PetCare Company challenging the company's claims about the contents of its products.

According to Adweek, Purina is accusing Blue Buffalo of false advertising, commercial disparagement, and unjust enrichment. 

At the heart of the lawsuit are Purina's claims that Blue Buffalo has misled consumers with claims that the company's products contain no chicken or poultry byproducts, corn, other grains, or artificial preservatives. Purina said it conducted independent testing of Blue Buffalo products and found that they actually do contain detectable amounts of those ingredients.

Purina also refuted Blue Buffalo's advertising saying that the "LifeSource Bits" in some products offer significant health benefits for pets, and alleged that Blue Buffalo's advertising misleads consumers about the ingredients contained in competitors' products, the Wall Street Journal reported.

Bill Bishop, Blue Buffalo founder and chairman, responded to the lawsuit by reaffirming the company's long-held stance that its claims about the ingredients of its foods are true and verifiable. He also said the company looked forward to challenging Purina in court. 

"We will prove these and other matters in the court with good reliable evidence, and we look forward to disproving the voodoo science that Nestle Purina relied on to support their outrageous allegations," Bishop wrote in a Blue Buffalo news release.