Why Do Dogs Have Blue Eyes? Unveiling the Mystery!

Blue Eyes Due to Hepatitis

Canine hepatitis, also known as "blue eye disease," is an acute, highly contagious septicemia affecting dogs. It is caused by direct contact with the secretions or excreta of infected dogs.

In the early stages of infection, the symptoms resemble those of a severe cold, including a rise in body temperature, lethargy, loss of appetite, and sticky discharge from the eyes and nose. However, there is no coughing. As the illness progresses, dogs may experience vomiting, diarrhea resembling jam, and bleeding spots or spots on the gums. Some affected dogs may exhibit abdominal enlargement, while others may develop a blue film over one or both eyes, which later becomes transparent in the cornea after a few days.

The hepatitis virus is particularly resilient, as it can survive in an infected dog's kidneys for up to 69 months after recovery. During this period, healthy dogs can still contract the virus if they come into contact with the urine of a recovered dog. Therefore, it is crucial for pet owners to ensure their dogs are vaccinated annually at a reputable veterinary clinic to maintain their health.

Blue Eyes Due to Cataracts

As dogs age, they may develop cataracts due to degenerative changes in the lens, or they may acquire them due to other factors. This condition causes a white film over the eye, which may have a bluish sheen, turning the eyes blue. In the later stages of cataracts, dogs' vision is severely impaired, significantly affecting their quality of life. Fortunately, many hospitals in Shanghai now offer cataract surgery for dogs, restoring their sight.

Blue Eyes Due to Albinism

Complete albinism in dogs is rare in real life (due to severe defects that make survival difficult). In cases of extreme albinism, the cells in the white fur areas cannot produce pigment, as seen in some border collies where one side of the face appears white with blue eyes. However, this is a concerning trait and such dogs are not recommended for breeding.

Natural Blue Eyes

The Husky breed has a unique gene that controls blue eyes. A repeat of the ALX4 gene on chromosome 18 has been found to be associated with blue eyes, and this gene is a key factor in the blueeyed Huskies.

Blue Eyes in Puppies

Newborn puppies often have a blue film over their eyes, which gradually disappears as they grow older. The blue hue in a puppy's eyes is not actually the color of their eyes. Puppies are born with blue eyes because the melanin in their eyes takes several weeks to develop. Without melanin, light reflects and refracts off the iris, giving the appearance of blue eyes. As the puppies grow, melanin starts to form in the iris, leading to the development of their final eye color.

There are numerous factors that can lead to blue eyes in dogs, but the most common ones have been outlined here. As long as the blue eyes are not pathological, pet owners should not be overly concerned. If your pet shows discomfort due to blue eyes, it is important to seek veterinary care promptly.