You may be asking ‘What is a lethal white Aussie?’ More accurately, these Aussies are double-merle or homozygous merles. The 'lethal white' tag comes not from any lethal genetic defect, but from the fact that many are destroyed at birth because of their potential deafness and/or blindness. You can click on the Amazing Aussies link here on my blog to find out the complete story, but in a nutshell, a lethal white Aussie is a double-merle Aussie, that is, one whose both parents carry the Merle gene. The merling gene in a dog washes out skin and fur pigment, which gives it that silvery, mottled grey and black color, or in some cases, a red and tan mottled color. In a litter of Aussies born from merle parents, statistically the litter can be 25% double merle - MM. The double merle genes will wash out all or most of the pigment, leaving the dog with no pigment in its inner ear hair. If these tiny hairs do not have pigment, they will not transfer sound. Therefore most of the lethal white aussies are deaf, and some can be blind or partially sighted too.
Most white aussies are found in shelters and animal control facilities, left there by guardians who do not want to deal with them, or irresponsible breeders who can't sell them. I adopted Annie from our fantastic local humane society. She has good eyesight but is completely deaf. She excels in agility classes.
The Lethal White Aussie is a loving, capable companion. It just needs extra attention for its special needs such as a fenced yard and diligent caregivers. Many Lethal White Aussies learn fluent sign language and can compete in agility competitions even if they are deaf or visually impaired. Some are Certified Therapy Dogs.