Uveitis & Cataracts

Uveitis refers to an inflammation of part of a dog's eye causing visible discoloration. If left untreated, uveitis can actually lead to more severe eye problems, including cataracts and blindness. Although veterinarians know uveitis can be caused by a large number of problems, in three-fourths of cases the cause of the inflammation is not determined.

The uvea is the middle of three layers (or tunics) that form the wall of the eye. This layer keeps the eyeball supplied with blood and also keeps the lymphatic fluid drained. This tunic is also divided into three separate sections: the choroid, the iris and the ciliary body. Uveitis occurs when one or more of these subsections become inflamed. As a result of uveitis, the dog will have eye redness, eyeball swelling, eye discharge and pain.

Uvea inflammation can occur for a number of reasons. Infections caused by bacteria, viruses, parasites, or even fungi can lead to this eye problem. Diabetes and other metabolic diseases can also cause uveitis. Autoimmune diseases, high blood pressure, damage to the eye lens, eye injuries and toxemia have all been identified as causes of uveitis. However, only 25 percent of cases have a known cause. The most noticeable symptom of uveitis is the red coloration of the eyeball. Other signs a dog may exhibit include keeping one eye shut (bright light causes more discomfort), eye cloudiness, excessive tearing, and sometimes bleeding into the eye region. A veterinarian can diagnose uveitis by measuring the intro-ocular pressure in the affected eye. Lower than normal pressure is suggestive of uveitis.

Without proper treatment, uveitis can cause complications, including cataracts and blindness. Cataracts form slowly as the lenses of the eyes become more opaque, preventing their proper function, which eventually leads to blindness. In fact, cataracts are the leading cause of blindness among dogs, according to Veterinary Vision. In addition to cataracts, uveitis can also lead to glaucoma or the development of scar tissue between the lens and iris.

Because uveitis can be caused by a number of problems, veterinarians may need to try several options before finding the right treatment. For example, if an infection is responsible, different treatments may be needed based on whether it was caused by a parasite or bacteria. Pain medication is usually given to help relieve the dog's discomfort as well. Generally, once the right treatment is identified improvement begins within 24 hours. However, cataracts and other potential complications require additional treatments. Surgery is usually used to remove cataracts or scar tissue while medications can be used to reduce the intra-ocular pressure associated with glaucoma.