The prevalence estimates for mitral valve disease in the Cavalier King Charles spaniel range between 11–45% (Hyun, 2005; Haggstrom et al., 1992; Darke, 1987). According to the literature searched, each of the top 50 breeds was found to have at least one aspect of its conformation predisposing it to a disorder; and 84 disorders were either The Cavalier King Charles Spaniel is a delightfully affectionate, playful, intelligent little dog that repays his owner’s care and attention with an endearing devotion and a wagging tail. The Cavalier is very happy, active and fearless despite its diminutive size. It is very loving to its family and a good companion for both children and seniors. neswym.