CERTAIN charms of New York City living — the infinite brunch options, the 24-hour bodegas, the Museum of Modern Art — are no doubt lost on many pets. Even so, plenty of owners believe that the city is ideal for dogs, offering endless opportunities for socializing and sniffing at dog runs, hydrants and doggy day care centers. Working late? Dog walkers abound. Square footage is tight? More opportunity for canine-human bonding.