The breed may have any eye color or combination of colors including blue, brown, green, or amber. Catahoula's are known for having heterochromia which could result in a number of different eye variations: Deafness is one of the major genetic faults common in Catahoulas and is associated with individuals that are excessively white in color and deafness attributed to a lack of melanocytes. Breeders are often unwilling to allow deaf Catahoulas to leave their premises and will generally euthanize deaf pups. Puppies born from a litter where both parents have the merle color pattern have a 25% chance of turning out to be blind, deaf, or blind and deaf. These puppies are often referred to as 'double merles'.