We suppose it was inevitable. Late one afternoon last spring, we espied Ralphie the Pug, Ranger the Rottweiler, Ginger the Pomeranian and Lizzie the Golden Retriever mingling easily in a corridor at Biltmore Fashion Park. Neither the dogs nor their masters seemed to have much familiarity with the meaner streets of our great metropolis. Both pups and humans were well-groomed, spiffy, comfortable in their skins -- or fur. Every Thursday (except during the hot summer months) from 6 to 8 p.m., up to 80 canines crowd into this puppified shop on the venerable mall's north side to gobble their treats -- some of which seem more fitting for the two-legged animals. And they say it's a dog's world. So it is.