You can dress her in a parka, crimp her fur, and keep her in your purse, but don't forget: Your dog is still an animal. A pack animal, and it's time to re-acquaint Princess with her long-forgotten species. The Martell dog park is a wedge of suffering grass in the middle of a severe cement landscape, rimmed on the north and east by I-195 ramps, the west by a condo tower, and the east by Biscayne Bay and the sex offender-habitated Julia Tuttle Causeway. But to the finally unleashed urban dog, this is nothing less than heaven: a tract large enough for an epic game of catch (it's about the size of a little-league park) ornamented with a half-dozen big trees to pee on and, if you time the visit right, a plethora of friends equally interested in ass-odor appreciation. Arrive after 5 p.m. on a workday — parking is tricky, so it's wise to drop off your car a few blocks away and make the walk — and the place is packed with downtown-residing yuppies and their toaster-size canines. Run free, purse dogs!