Sarah Stalnaker, DVM
Cataracts are one of the most common conditions that affect dog’s eyes. However, in cats they are fairly uncommon. They form in the clear structure located just behind the pupil of the eye called the lens. This structure aids vision not only by allowing light to hit the retina, or the back portion of the eye, but also by helping the retina focus images. When a cataract starts to form it decreases vision and eventually may lead to complete blindness of the eye. There are several different causes of cataracts. Some of the more common causes include dogs who are born with cataracts or who are genetically predisposed to form cataracts as they age. Diabetes can also cause cataracts. Any type of injury to the eye can eventually cause a cataract to form due to the inflammation it may cause to the lens.
What should you do if you dog’s eyes start to appear cloudy or their vision seems to be decreasing? First, have your pet examined by your regular veterinarian. Many dog’s eyes will start to appear cloudy as they grow older. Your veterinarian can determine whether this cloudiness is a cataract or if it is a more common condition called nuclear or lenticular sclerosis. Nuclear sclerosis is a condition where the fibers in the lens compress causing the lens to take on a more whitish color. Many dog’s lenses will become cloudy with nuclear sclerosis as they age but it will not affect their vision and no treatment is needed.
If your dog is diagnosed with a cataract, surgery is the only way to completely remove it. However, not all dogs are candidates for surgical removal. Your veterinarian may refer you to a veterinary ophthalmologist who will perform several tests to examine the retina and determine if the rest of the eye will be able to function correctly after the cataract is removed. A blood test will also be performed to confirm that your dog is in good health for general anesthesia. Cataract surgery has a greater than 95% success rate.
What if you are told your furry friend is not a candidate for surgery or the expense of surgery is too great? Most dogs live extremely happy, healthy lives even with cataracts that have caused complete blindness. Unlike humans, dogs rely on their other senses, especially their sense of smell more than on their eyesight. They do however need extra assistance when taken to new environments and even though most still love to run and play, they can not be left outside without supervision.