The Cavalier King Charles Spaniel is a small spaniel classed as a toy dog by The Kennel Club and the American Kennel Club, that originated in the United Kingdom. Since 2000, it has grown in popularity in the United States and ranks as the 19th most popular pure-breed in the United States. The breed has four recognized colors. In some Blenheim dogs there is a chestnut spot in the middle of the forehead: this is called the 'Blenheim' spot. The fourth color is known as Tricolor, which is black and white with tan markings on cheeks, inside ears, Although symptoms of syringomyelia can present at any age, they typically appear between six months and four years of age in 85% of symptomatic dogs, according to Clare Rusbridge, a research scientist. Symptoms include sensitivity around the head, neck, or shoulders, often indicated by a dog whimpering or frequently scratching at the area of his neck or shoulder.