Though the official start of summer is still more than a week away, it seems as if the dog days are already upon us. Well they soon will be. On Thursday at Supper, anyway. This Thursday and every Thursday throughout the season, Supper will offer a miniaturized version of its elusive Supper Dog — that’s the housemade wiener wrapped in bacon, deep fried and nestled in a house-baked bun with barbecue onions and beer mustard — during happy hour. Previously that dog was only available during brunch. Supper’s happy hour runs Tuesday through Friday from 5 to 7 p.m. and features specially priced wine, beer and cocktails, plus a host of other hors d’oeuvres that are available at a reduced price, or three for $12. But Thursday’s the only day you can get the Supper Dog.