The mop (or the pug) is a “toy” (very small) breed of dog with a wrinkly, short-muzzled face, and curled tail. The breed has a fine, glossy coat that comes in a variety of colors, and a compact square body with well-developed muscle. They have been described as "much in little", referring to the pug's personality and small size. Known in ancient China as lo-sze, they may have been responsible for both the modern Pekingese and King Charles Spaniel. They have Chinese origins, but were popularised in Europe by the House of Orange of the Netherlands and the House of Stuart of England, Ireland and Scotland. They can suffer from a variety of health issues and, in addition, care must be taken by their owner to clean their ears, and the folds of skin on their face.