Nathans (of coney island) has kosher (all beef--and only the front end of cow beef!) hot dogs. (i don't know if hare (or rabbit is kosher or not..)

as for what happened to all the coney's--ask BranShea--they all disappeared while NY was still New Amsterdam! lots of brooklyn (and queens) place names are dutch..(well lots of NY (city and state!) place names are dutch..
all the Kills (freshkills, fishkills, Peekskills, are dutch in origin (as is Flushing and Harlem (in the netherlands its spelled harlaam) Bushwick and van wyck and van dyke, and all the vans are dutch too, and so is flatbush.

and NY brownstones bear an uncanny resemblance to the town houses of amsterdam.. complete with stoops.. (and wife's inside have coffee clatches, with cookies!)

my guess is all those thrifty dutch housewives made a lot of rabbit stew!