Since 2000, it has grown in popularity in the United States and ranks as the 19th most popular pure-breed in the United States. It has a silky, smooth coat and commonly a smooth undocked tail. The breed standard recognizes four colors: Blenheim (chestnut and white), tricolor (black/white/tan), black and tan, and ruby. The breed is generally friendly, affectionate and good with both children and other animals; however, they require much human interaction. According to the Canine Inherited Disorders Database, the condition requires continual treatment and if untreated may result in partial or total blindness. This disorder can decrease or heal over time.A 1999 study of Cavaliers conducted by the Canine Eye Registration Foundation showed that an average of 30% of all Cavalier King Charles Spaniels evaluated had eye problems.