Aussie Genetics Fact Sheet: Excess White by C.A. Sharp The breed standards limit the amount of white markings an Aussie is supposed to have. The Australian Shepherd Club of America standard says that areas around the eyes and ears should be “dominated” by non-white coloring and that a white collar should not extend beyond the point of the withers. The American Kennel Club standard is very specific about where white may and may not occur on the dog. Both standards disqualify dogs with white body splotches. These restrictions are not made just to produce a preferred look. Australian Shepherds with more than the allowed amount of white may have problems. If two merle dogs are bred together, some puppies will inherit two copies of the merle gene. These puppies almost always have significant defects in eyesight and hearing and they almost always exhibit more white than is allowed by the standard. Dogs of any color that have a great deal of white on or around the ears may have some hearing loss. This is true not just for Aussies, but for many other breeds as well. If a dog produces too much white when one parent of the cross is not merle, the cause is white trim genes. Either one or both parents are carrying a recessive version of the gene that causes too much white, or the parents have some combination of modifier genes that came together to cause unwanted white spots or over-extended white trim.