What common physical characteristic in some Koolies is sometimes linked to potential visual or auditory impairment?

Answer

Merle coloring

Some Koolies can exhibit merle coloring, which is sometimes associated with visual or auditory impairment if breeding practices are not managed responsibly.

What common physical characteristic in some Koolies is sometimes linked to potential visual or auditory impairment?
animalDogExpectancyKoolie