The pericardium is a tough, layered sac that wraps around the heart. When the heart beats, it slides easily within the sac. Normally, only 2 to 3 tablespoons of clear-yellow pericardial fluid are present between two layers, which lubricates the heart's movements within the sac.
Biewer. The Biewer (pronounced Bee-vair), also known as the Biewer Terrier, Biewer a la Pom Pon, Biewer Yorkshire Terrier, Biewer Yorkshire, or Biewer Yorkie is a variant of the Yorkshire Terrier.
Originally the Yorkie was bred for the purpose of catching rats in mines. They were also used for hunting to borrow underground after badgers and foxes. The ancestors of the Yorkshire Terrier are the Waterside Terrier, a small Scottish breed with a long blue-gray coat.