To cheer him up, race organizers named him the official dog of the race and unveiled a nice portrait of him. Also according to CBS, "Spencer was given a limousine ride to Fairmont Copley Plaza, where he was presented with gifts in the lobby including a personalized race bib, and a goodie bag donated by Boston Barkery."
Every year, in Ashland, Spencer holds up a "Boston strong" banner between miles 2-3.