Dogs are an ease to please. A couple of acres of rolling green space on which to gambol. Freedom to relieve one's self on one's own schedule. That, and the chance to practice the species' appallingly crude greeting ritual: bum sniffing. The Barkham at Markham Dog Park sports more room and better-kept grounds than the area's other dog parks, where an hour of fun usually requires a bath at home. For when us bipeds need a trot, there's a fitness track in both the park's big dog and little dog sections. A pavilion makes this one of the few parks where you can have a picnic and unleash your dog. Plus, with the Everglades bordering the park to the west, this is real country air. It's a glorious way to spend a spring Sunday afternoon, and the exertion is liable to make that mutt a little less obnoxiously peppy through the evening.