Just seven months after tapping Omnicom's GSD&M as its agency, Petsmart is bringing the bulk of its advertising in-house.

The move comes after Petsmart was bought by a consortium led by BC Partners in December. That deal became final in mid-March. Two weeks later, Phil Bowman, exec VP-customer experience, a role that oversees marketing, left the company. He has since been replaced by Eran Cohen, whose hire was announced as part of a new leadership team in the wake of the private-equity acquisition.

Bringing its creative in-house isn't new for the retailer. Prior to hiring GSD&M, the company had fielded much of its marketing in-house in recent years.

"While we appreciate the efforts of GSD&M, we've decided not to continue our partnership with them," said Michelle Friedman, a spokeswoman at Petsmart. "We will resume management of all creative work with our in-house team."

Said GSD&M in a statement: "We want to thank our client partners for the opportunity to create bold work in a true collaboration. We are proud of the work we created together and wish everyone at Petsmart the best during their transition."

The agency in February launched a campaign called "Petsmart partners in pethood," which included spots directed by Christopher Guest.

Petsmart spent about $113 million in U.S. measured media in 2014, according to Kantar Media, up from nearly $105 million in 2013.

The loss of Petsmart comes after the agency recently parted ways with Marshalls. Ace Hardware, which the agency has also handled, also went into review. In the past year, GSD&M has picked up the Hampton hotel business (August), the Northwestern Mutual account (July) and media planning and buying, along with select creative projects for Chipotle (last May.)

Contributing: Ashley Rodriguez