Blue Buffalo Ltd. has been targeted with a putative class action alleging the company deceptively marketed its pet food as being free of chicken by-products, corn, other grains and artificial preservatives.

Plaintiff Rachel Stone, who filed the suit in the U.S. District Court for the Southern District of Illinois on May 7, claims another misrepresentation by Blue Buffalo is that its pet food has superior nutritional value compared to competitor products.

The suit alleges that Blue Buffalo, headquartered in Wilton, Ct., violated Illinois and other states’ consumer fraud statues by selling and advertising the pet food with false claims about its ingredients. Read the complaint in Stone v. Blue Buffalo Co.

Stone says she purchased the defendant’s pet food including Life Protection formulas Chicken & Brown Rice recipes many times during the past year and relied on the company’s claims.

“Multiple investigations have revealed the company’s claims are false,” including one that “discovered substantial amounts of poultry by-products in defendant’s pet food,” the complaint says.

The suit estimates the number of potential class members in the thousands, based on the number of nationwide retail outlets that sell Blue Buffalo’s pet food.

A separate lawsuit filed by pet rival Nestlé Purina PetCare Co. against Blue Buffalo in a Missouri federal court on May 6 makes similar allegations about the company’s ingredients.

In its suit, Purina alleges that, in some Blue Buffalo products, chicken and other poultry by-products comprise more than 20 percent of the product by weight.

“Contrary to Blue Buffalo’s so-called “True Blue Promise,” many Blue Buffalo products also contain corn, other grains, and artificial preservatives when they promise otherwise,” Purina claims.

Laura Castro contributes to