Why are a dog's whites red? - briefly
The red color in a dog's eyes is due to the presence of blood vessels beneath the thin conjunctiva, which reflects light differently compared to humans. This distinctive appearance is a normal part of canine eye anatomy and does not indicate any health issues.
Why are a dog's whites red? - in detail
The color of a dog's eyes is determined by several factors, including genetics and the presence of certain pigments in the eye. The "red" or pinkish hue often seen in the whites (sclera) of dogs' eyes can be attributed to the visibility of blood vessels beneath the surface. Unlike humans, who have a thicker, more opaque sclera that obscures these vessels, dogs have a thinner and more translucent sclera, allowing the underlying vasculature to be more visible.
Genetically, some breeds are predisposed to having more prominent blood vessels in the eyes, which can enhance this red appearance. Additionally, aging or certain health conditions can cause the sclera to thin further, making the blood vessels even more noticeable. While the pinkish hue is generally considered normal for dogs, any significant change in color or the appearance of red spots should prompt a veterinary check-up to rule out potential issues such as conjunctivitis or other eye disorders.
In summary, the redness observed in a dog's whites is primarily due to the visibility of blood vessels beneath the thin and translucent sclera, which is influenced by genetic factors and can be accentuated by age or health conditions.