What's Wrong With White Aussies?
An Australian Shepherd with a coat mostly snowy white sounds beautiful, but for decades all the breed standards have made having even so little as a third of the coat white a disqualification--meaning such dogs cannot be exhibited at dog shows and should not be bred. Why?
Aussies with mostly white coats can be produced when two merle Aussies are bred together. Merle is the patch-work coloring (black and grey or liver and buff) most associated with the breed. When a puppy inherits two copies of the gene for merle, it will usually have a lot of white in its coat.
If these puppies only had lots of white, there wouldn't be a problem. Unfortunately, most of them are also blind, deaf or both. This is the reason that the breed standards disqualify white dogs and why knowledgeable breeders will not raise them.
Life for a dog which is blind or deaf can be difficult. The defects cannot be cured or corrected by surgery or other treatments. Sometimes such dogs will tend to bite when startled. People who own white Aussies must take extra care all through their dog's life--which can be 15 years or more--to make sure the dog cannot harm itself or anyone else because of its disabilities.
If someone offers to sell you a white Aussie, don't buy it. If you already have one, have your vet check for defects in its vision and hearing, then take whatever precautions are necessary to protect your dog and those around it.
White Fright
The subject of white, or mostly white, Aussies is a contentious one wherever Aussie people congregate. It has sparked more than one "flame war" on the Internet discussion lists. Too much white is "bad" and people who keep such Aussies are branded as ignorant or irresponsible. As a retired breeder, an authority on Aussie genetics and (gasp!) the owner of a homozygous merle bitch, now deceased after a long and happy life, I suppose I ought to address the issue.
Before you start lighting your kindling: I do not recommend that people do anything to promote keeping white Aussies by most people under most circumstances.
Predominantly white Aussies are almost always the result of merle-to-merle breeding. These homozygous (meaning "two like genes") merles have inherited the merle color gene from both parents. They are usually, but not always, blind and/or deaf. The defects are variable, so the amount of vision and hearing loss will range from little to total with most tending toward the bad end of that scale. The eye defects result from improper development of the tissues of the eye while the loss of hearing is attributable to a lack of pigment in the inner ear.
I have heard people say repeatedly that homozygous merles also suffer other kinds of defects, but I have found no hard evidence of this in the veterinary literature. It has not been the case with the homozygous merle Ausses of which I have personal knowledge. I don't know if the lack of these other defects is because we keep so few of these dogs or because they do not happen. Their presence in other breeds has been questioned and may be coincidental.
If you breed a homozygous merle, whatever the breed, you should only do so with a non-merle mate. And unless you have considerable experience in that breed, I would discourage you from doing it at all. If you breed a homozygous merle, all of its offspring will probably be merle.
I say probably, because sometimes something called "germinal reversion" occurs and a homozygous merle will produce a non-merle pup. This has been reported in the scientific literature in Aussies (Sponnenberg, J Hered, 1984) and there are anecdotal reports of it happening in Shelties and Collies. These non-merle pups are not "phantom merles" (more properly termed cryptic merles.) If bred to other non-merles, all their pups are non-merle.
Homozygous merle Aussies are usually, but not always, predominantly white. This is why the standards discriminate against white coloration beyond an "irish" pattern (blaze, collar, chest, underbody and legs) and why people are discouraged from keeping white pups. But it is possible to have a "normally" marked merle Aussie that is also homozygous.
Betty Nelson, long the chair of ASCA�s former Genetics Committee, had a homozygous merle bitch who was a medium blue with a stripe down her nose, a white throat and chest, one white foreleg and white toes. Hardly "full white trim". But for her line this was a lot. She was also light in color compared to the normal deep pigmentation of her line.
The situation is similar in breeds which also have merle and do not have white markings. I once asked a Dachshund breeder about "dapples", which is what they call merles. He told me that the homozygous merles in some lines had a lot of white but in others they had very little. This ties in with what I know of Aussie lines with little white.
There are also predominantly white Aussies which are not homozygous merles at all. The S-locus gene gives us our acceptable white markings. There are several alleles (forms of the gene) at this locus. They code for everything from no white, like a Dachshund, to almost all white, like some Fox Terriers. Aussies with �too much white� that were not homozygous merles were once far more common than they are today. I can remember seeing several when I first started in the breed in the early 70s. Look at the historical section of ASCA's first yearbook for pictures of some of them. White Aussies are rare today because we have been slowly eliminating the "more white" forms of the S gene from our gene pool by not breeding Aussies with more than allowable white. (Though the preference for white trim on the show dogs does have some pushing the envelope.)
If you don't want to produce homozygous merles in your litters, it's easy to avoid doing so: Don't breed two merles together. That's the route I took when I was breeding. If you do plan merle-to-merle breedings you must decide beforehand what you will to do with the homozygous pups.
If you want to keep a homozygous merle, you must be willing to devote yourself to keeping it safe from dangers it cannot hear or see for its entire lifetime. These dogs are not for everybody. While my Moby was one of the sweetest Aussies I've ever owned, I've known of others whose temperaments were terrible. Bad temperament is not directly a result of the dog being a homozygous merle. But if a dog is genetically predisposed to temperament faults the sensory deprivation and ease of startling them with things they cannot hear or see may push borderline dogs over the edge and make those who would have been bad even worse. Proper socialization is necessary for any Aussie, but doubly so for a homozygous merle.
If you do keep a white Aussie, you should be doing everything you can to educate people who see the dog and might think it is pretty about the problems of homozygous merles. The rescue organizations have enough trouble placing sound dogs. They don't need more pound puppies who were dumped because ignorant buyers discovered after the fact that the white Aussie they chose had a problem. Or because people decided their noble intention to "save" a blind, deaf pup had become too much bother.
If you produce a homozygous merle, you have a responsibility to take care of it one way or another. If you acquired it, you have made a life-long commitment to caring for a handicapped animal. If you want to breed it, you damn well better know what you are doing.