Homozygous merles or double merles are commonly referred to as lethal whites. As the name would suggest, these dogs are born with excessive white coloration and often are destroyed immediately after birth due to the high risk of impending health problems.
In addition to excessive white coloration, these puppies may also be born blind, deaf, disfigured, and with partial or missing eyes and/or organs.
Homozygous merles may only result when a merle is bred to another merle and the puppy receives 2 copies of the merle gene; 1 from each parent. Blue merle to blue merle, red merle to red merle, blue merle to red merle. This breed detriment is completely preventable through responsible breeding.
Not to be confused with homozygous merles, pattern whites have only 1 copy of the merle gene but have excessive and/or unacceptable white coloration. Extra attention should be given to loss of coloration surrounding the eyes and ears, especially if the effected side has a blue eye. This loss of pigment is directly related to a heightened risk of blindness and/or deafness.
Hartspride does not breed merle to merle and only breeds dogs with acceptable and/or minimal white.
For more information regarding homozygous and pattern whites please click the link below: