In November 1964, LIFE magazine noted that "a small dog with a sweeping hairdo and a peppery disposition" was pushing the poodle aside as the elegant canine accessory-of-the-moment. LIFE also noted that the small, dynamic Yorkie -- for it was none other than the Yorkshire Terrier to which the magazine devoted a multi-page feature -- "is no lap dog. It has the dash and spirit of all terriers and is a better ratter than most cats."
The image of a fearless rat-killer is hardly the first that comes to mind, of course, when one thinks of the Yorkie -- and the Nina Leen photos in that LIFE feature focused on the breed's cute, lively nature rather than its innate (if rarely exercised) ferocity. But the point was clear: while small in stature, the Yorkie has huge appeal.
Here, as the 138th annual Westminster Dog Show gets underway in New York, LIFE presents some of Leen's pictures from 50 years ago -- photos celebrating a rare and singularly winning breed.
Liz Ronk, who edited this gallery, is the Photo Editor for LIFE.com. Follow her on Twitter @lizabethronk.