Dewey Beach is one of the ONLY beaches on the East coast that allow dogs to run free, without a leash. I have to say that I completely understand why dogs are not allowed on beaches.
During the Summer dogs are allowed on the beach after 5:30, that's about the only restriction.
But, please, pick up your dogs poop, don't be "that" person. There's no excuse, poop bags are right there next to the trash can.