Chronic stress, or a constant stress experienced over a prolonged period of time, can contribute to long-term problems for heart and blood vessels. The consistent and ongoing increase in heart rate, and the elevated levels of stress hormones and of blood pressure, can take a toll on the body.
Excess Tearing. The most common cause of tear stains in dogs is excess tearing or epiphora, which makes the hair and skin around the eyes damp. This can lead to the growth of bacteria and yeast. Red yeast, which produces a reddish brown discoloration of the face, is a common cause of tear stain problems.
Eventually, the leaking vitreous fluid gets behind the retina, separating the retina from other layers of the eye. The retinal tear that triggers a retinal detachment sometimes is caused by trauma. More often, it is caused by a change in the gel-like consistency of the vitreous fluid that can occur as a part of aging. This age-related change can occur unpredictably in older people, and there is no way to prevent it.