“Lani,” one of 17 purebred Shar Peis rescued by the MSPCA last month from “filthy conditions” in a Braintree home, escaped Tuesday night at around 5 p.m. when her new owner, Teri DeFilippo of Wareham, brought her home from the MSPCA’s Boston Adoption Center. Lani slipped through her leash and took off running.