“Lethal Whites” or double merles are purebred dogs that are typically deaf and sometimes blind as a result of breeding a merle with another merle. Typically this happens with backyard breeders who are more concerned with getting pretty puppies to sell than with their health. It is also common with inexperienced or first-time breeders.
They are called “Lethal Whites” after a similarity in physical appearance to a lethal gene in horses that creates a solid white, blue-eyed foal. However, the only thing “lethal” about being born a Lethal White puppy is that many breeders drown or abandon these pups at birth because they cannot be registered or sold.
Lethals are most common in the herding breeds: Australian Shepherds, Border Collies, Shelties, and Collies. They are also found in Dachshunds, Great Danes, Boxers, and Pit Bull Terriers.
A normal merle is either red or blue. A red merle has a distinctive spotted pattern of either red on white or dark red on lighter red. A blue merle has the same spotted pattern, but with blue on white or silver on dark blue. Breeding any two merles with each other creates double merles or Lethal Whites. A typical merle to merle breeding produces 25% solid colored pups, 50% merle pups, and 25% double merle pups.
Most Lethal Whites are predominantly white in color with a few patches of red or blue merle. Typically they have normal-looking blue eyes or smaller-than-normal pink eyes (microopthalmia). Usually, the nose is partially pigmented, leaving patches of pink on an otherwise black nose.
If the ears are entirely white, then the dog is usually deaf. If the fur is white and the skin is pink around the eyes, then the dog may be blind or visually impaired. Most Lethal Whites are deaf or hearing-impaired to some degree. Some are blind or have some degree of visual impairment.
Puppies born deaf and blind don’t know that they are impaired in any way. They still run, wrestle and play with their siblings, just like any other puppy. Deaf/blind puppies still love petting and cuddling as much as any other dog does. However, they perceive their entire world through touch, so they do require a sensitive and compassionate owner who is willing to use touch signs for training.
Some examples of adoptable red merle, blue merle and Lethal White dogs from the greater Nashville area are attached. For more detailed information on Lethal Whites, see Amazing Aussies Lethal White Rescue.