Domestic cats throughout the world have at least twenty-three well-known single-gene traits. These traits affect coat color, color distribution, the marking patterns on the coat, ear conformation, tail conformation, and fur type, including length. In combination with various body types, these genes are responsible for the distinguishing characteristics of the over three dozen cat breeds recognized in the United States alone. In order for cat breeders to determine the recessive traits carried by a given cat, time-consuming and expensive test breeding is necessary. The identification of genetic markers for some of these traits will allow cat breeders to determine carrier status with a blood test. Knowing a cat’s carrier status would reduce the need for test matings. These traits can also be used in forensic and other biological applications.