Through the years, Pet Valu, which was acquired by a private equity firm in 2009, aggressively expanded its footprint. With stores that averaged 3,000-5,000 square feet, Pet Valu was able to fit into spaces that could not house a Petco or PetSmart, which average 10,000-15,000 square feet, explained Amanda Lai, manager at McMillanDoolittle, a Chicago retail consulting firm.