Elbow Room and Elbow Grease.

WHEN strangers approach, there's a fierce bark behind the closed door of the Blitz family's 1899 American Foursquare house in Kensington, Brooklyn. But on close inspection, the dog, Magda, turns out to be just 10 inches tall, and pretty enough to be carried around in a socialite's Louis Vuitton bag. ''She's a Can Hardly,'' said Dori Dietz Blitz. Meaning the family can hardly tell what kind of dog she is. [ABSTRACT FROM PUBLISHER]