The eye is like a camera with a clean lens for focusing. A cataract is a cloudy covering called opacity. Cataracts not only affect people but dogs as well. A thorough test by your veterinarian is the only way to obtain a diagnosis.
Cataracts progress in several stages. Cataracts do not interfere with your dog’s vision in the first or incipient stage. Stage two (immature stage) is when more of the lens is covered, causing blurry vision. When the entire lens becomes cloudy and all functional vision is lost, the disease has progressed into a mature cataract. Another condition can affect older dogs. A nuclear sclerosis is a bluish gray appearance on the lens of the eye which looks like a cataract but is more of a hardening of the eye through aging.
Cataracts have many possible causes with the most common being genetics. Although any dog can get cataracts, some breeds, such as the Bischon Frise, are more susceptible. Mixed breeds can also inherit cataracts. The next biggest cause is due to diabetes in your dog. Your diabetic dog can develop cataracts very fast, which can require a medical and surgical emergency. A toxic reaction in the lens of the eye due to certain toxic changes in your dog can also cause cataracts. Such conditions as retinal degeneration (progressive retinal atrophy or PRA), uveitis (an inflammatory eye condition of any cause) and glaucoma can result in the disease. Cataracts can also be caused by any type of trauma to the eye, nutritional deficiencies, aging (dogs over 8 years of age), birth defects, radiation (usually from prolonged radiation therapy for cancer of the head) and infection.
Symptoms you may notice in your dog include a bluish, gray or white color change inside the eye, a visible pain and squinting, signs of blindness (with your dog bumping into things), and being afraid to climb and do normal activities. The sooner the disease is detected and treated, the chances it can improve and be cured.
Your veterinarian will perform a series of tests to confirm the presence of cataracts, determining what is causing the change to your dog’s eyes and vision. Depending on those results, she may recommend a specialized veterinary ophthalmologist. Initially your vet will watch your dog for any obvious signs while he is walking. She will then evaluate the pupil size, symmetry and light reflexes. Other motion reflex tests may include moving a swift hand towards the dog’s face and dropping a cotton ball or other object nearby to check for reflexes and reactions. To rule out glaucoma, intraocular pressure of the eyes will be assessed. The eyes may be dilated as well to perform other tests with lights, a tear test while placing a fluorescent dye in the eye, and possibly some advanced testing, such as ocular ultrasound and electroretinography, to evaluate the retina and rule out concurrent retinal degeneration. The diagnosis of any or all of these tests will determine the proper treatment for your dog’s particular situation.
The only treatment for cataracts is surgery, which begins with ocular ultrasound and electroretinography. The surgery itself will be performed by the veterinary ophthalmologist, who will remove the cataract through a procedure which involves ultrasonic fragmentation of the lens itself. He will then implant an artificial lens to restore normal vision. Without the artificial lens, your dog will be extremely far-sighted after cataract surgery, with very little vision. Once surgery is completed, it will be crucial that your dog refrain from any exercise regimen for several weeks and also be required to wear an Elizabethan collar. You may need to apply an antibiotic or anti-inflammatory ointment or drops to the recovering eyes per the instructions of your veterinarian. He may also prescribe oral anti-inflammatory drugs and oral antibiotics. Re-examinations will be scheduled at 1, 2, 4 and 6 weeks after the cataract surgery as needed until your vet is satisfied that the surgery was a complete success and your dog is healed enough to resume normal activities.