The Planning Board on Thursday will hold a hearing on a special permit request from Picture Perfect Pets to open a store at 376 Cambridge St. that would offer dog training and pet portrait photographs. The board will also continue a hearing into a proposal by Terry Ave LLC to expand its self-storage facility, Storage Unlimited, at 17 Terry Ave. The applicant needs site plan approval and a special permit for the project, according to Don Benjamin, the town’s senior planner. The board will resume a hearing into a request by RC Trust for a minor engineering change to its special permit to develop Middlesex Marketplace, a mixed-use development under construction at 90 Middlesex Turnpike. It also will hold a hearing on a special permit application by the owners of Mughals Indian Cuisine at 184 Cambridge St., to change the name of the restaurant to the Bombay Club.