You from NY of all places and the idea of bomb sniffing dogs at a major sporting event strikes you as strange?
I mean I'm all for a good conspiracy but I see a lot of people making mention of there being army guys on the roofs of buildings and bomb sniffing dogs as being odd which in reality given the event and circumstance (big city, Patriots Day) really aint that out of the ordinary for a major marathon.
They probably knew something was gonna go down but failed to stop it.