The Unleashed by Petco Store didn't work out in NoMA
One concept that needs to be emphasized more in planning retail in DC is the difference between neighborhood serving districts and "regionally serving districts" even though in this case, regional means "multiple neighborhoods" rather than multiple cities.
In Manhattan, it would be how Union Square serves as a major retail center, while commercial districts in Lower Manhattan have smaller groceries, hardware stores, specialty markets, dry cleaners and other service establishments etc.
In DC, Friendship Heights, Columbia Heights (the Target anchored DC/USA shopping center has other retailers including DSW Shoe Warehouse, Bed, Bath and Beyond, Modell's Sporting Goods, and Best Buy), and other areas act as regional destinations.
Probably pet supply stores have a "retail trade area" of the neighborhood and a bit beyond. People aren't likely to travel too far outside of their neighborhood for pet supplies. So putting such a store in a place with large mostly apartment and condominium buildings probably wasn't a good move on the part of Petco.