You & Your Pet by Dr. Wise

Rhode Island Veterinary Medical Association 11 South Angell Street #347 · Providence, RI 02906 (877) 521-0103 (866) 277-0238 Toll-Free ·Fax

I have recently noticed my 8-year-old Chihuahua's eyes seem cloudier than usual.  Does he have cataracts?   What can I do?

It is normal for the lens of a dog's eye to become a slightly grayish blue or milky color when the dog reaches about eight years of age.   This is caused by a hardening of the lens which happens normally as dogs get older.   It is called nuclear sclerosis and does not affect overall vision.   Your veterinarian can help you determine if your dog has hardening of the lens or if there are cataracts.

A cataract is any abnormal cloudiness of the lens.   It can be the size of a tiny spot and not affect your dog's vision, or it can involve the entire lens and cause blindness.  The most common cause of cataracts is a genetic defect.  Cataracts can also develop after injury or inflammation in the eye or from diabetes.  The only treatment for cataracts is to surgically remove them, which is a very delicate operation.  It is important to make sure that your pet is a good surgical candidate.  Your veterinarian will perform a complete physical examination, and take blood and urine samples for testing to determine that your pet does not have any serious underlying medical problems.  If all the tests are normal, you will be referred to a veterinary ophthalmologist (eye doctor) who will perform a complete eye exam.  In order for the cataract surgery to be a success, the rest of the eye must be healthy.  Sometimes the lens is so cloudy that the eye doctor cannot see the back of the eye (retina).  In this case, a special test called an electroretinogram is needed to make sure that the retina is functioning normally. 

The lens removal surgery uses ultrasonic vibrations to liquefy the lens.  The lens is then removed through an incision less than half the width of a pencil eraser.  After surgery there are eye medications to apply frequently.  Once the lens is removed, your pet will be able to see and an artificial (intraocular) lens may be placed to refine your pet's overall vision.  He will be able to perform normal functions without any trouble.  If your dog is not able to have cataract surgery because of health concerns or other problems with the eye, do not be disheartened.  Dogs who gradually lose their eyesight adjust very well and are able to have a good quality of life despite their condition.

This information, prepared as a public service by the Rhode Island Veterinary Medical Association, answers problems Rhode Island veterinarians currently are seeing in their practices, as well as new developments in animal care.