A red merle Australian shepherd is a dog with a coat that has a "marbling" or mix of red and silver colors. The merle gene in dogs creates mottled patterns in the dog's coat in a variety of different colors.
Australian shepherds are one of several breeds who frequently have merle coats. "Red merle" is one of the colors in the official breed standards, as well as a black and silver pattern known as "blue merle." Dogs with merle coats often have one or two blue eyes as well. Although many merle Australian shepherds are healthy, the breed is frequently associated with deafness or blindness.