NEW YORK — The maker of Cheerios also wants to fill dog bowls.

General Mills said Friday that it plans to buy high-end pet food maker Blue Buffalo for $8 billion. It’s a return to the pet business for the more than 150-year-old company, which used to sell food for cats, dogs and birds back in the 1950s. And it joins other food makers in the pet business: Fruit-spread maker The J.M. Smucker Co., for example, owns Kibbles ’n Bits and Meow Mix.

The deal is also a way for General Mills to further diversify its business as more people seek less-processed foods, even for their furry friends.

“We’ve been serving all family members“ for years, said General Mills CEO Jeff Harmening. “And pets are part of the family.”

General Mills, whose revenue has fallen for three straight years, has been buying up food brands with fewer artificial ingredients as it deals with dwindling demand for its cereals and yogurt. In recent years, it bought Annie’s organic snacks and Epic meat bars made from bison, wild boar or lamb.