For many breeds of dogs, notably the Siberian husky, blue eyes are of genetic origin and do not indicate any signs of poor health. However, sometimes tinges of blue in the eyes are evidence of illnesses or eye conditions.
Some breeds of dogs, such as the Siberian husky, Cardigan Welsh corgi and border collie, have genes for blue eyes. Blue eyes are often results of the merle gene, which is related to dog coat coloring and dilutes the coloring of the pigment in the iris of the eyes, often making them blue, according to the Dog Coat Color Genetics website. Another cause of genetically blue eyes in dogs is a rare gene separate from coat coloring that causes one or both eyes to be blue.
Illnesses and Eye Conditions
Some illnesses and eye conditions make eyes appear to be blue. For example, infections canine hepatitis, a preventable yet deadly disease that affects several organ systems, often causes the corneas to appear blue. Cataracts, or clouding of the iris, and scar tissue on the eyes are other issues that make eyes appear to be blue -- cataracts may be milky white with a blue tinge. Genetically, blue eyes are typically no indication of health issues; however, dogs with genetically blue eyes have been linked to having hearing impairments, according to Washington State University.