Much to the surprise of many owners, cataracts can occur commonly in young dogs as well as geriatric dogs. Because we are used to cataracts in people being associated with age, it can come as quite a surprise when a dog as young as 1 or 2 years of age loses vision from cataracts.

By definition a cataract is any opacification of the lens. The lens is the clear structure behind the cornea and pupil. The purpose of the lens is to focus incoming light rays onto the retina so objects are in proper focus. If the lens becomes cloudy or opacifies, vision becomes impaired.

Cataracts in dogs can develop due to several reasons, but by far the most common cause is hereditary, followed by diabetes. Hereditary cataracts occur when a dog receives the gene carrying the cataract trait from both the sire and dam. These genes are well established within many breeds of dogs and even in mixed breeds. Age of cataract development is determined by the particular genetics of the breed, not the age of the individual dog. For example, certain dog breeds such as the Bichon Frise and Siberian Husky develop cataracts at 1 year of age!

Whether a dog is young or old, cataracts (opacified lenses) can be surgically removed by essentially the same procedure used for people. The major difference is that a dog will be placed under general anesthesia for surgery, and if both eyes are affected, both eyes will usually have surgery at the same time.

During surgery, once the cloudy lens material has all been removed through a very tiny incision, an artificial lens implant can be placed in the eye to restore normal focus. These lenses are safe and secure in the eye and remain throughout the dog’s life. Once cataracts are removed, a cataract cannot reform since there is no longer a biologic lens in the eye to develop a cataract. The artificial lenses are plastic or acrylic and therefore, not susceptible to opacification as the natural lens is.

This is also true for diabetic dogs that undergo cataract surgery. As long as a dog has no serious health problems, cataract surgery can be performed at almost any age – from 6 months to 16 years!

The cataracts in young dogs and diabetic dogs can come on very quickly and these eyes are at an increased risk of developing complications from the cataracts, such as inflammation and retinal detachment, very quickly. It is, therefore, important to have young dogs and diabetic dogs evaluated as soon as any cataract change is noted, preferably before total vision loss. The best success rate for surgery is in dogs operated on early rather than late!

This column is provided by the faculty of the OSU Boren Veterinary Medical Teaching Hospital.  The large volume of questions does not allow us to directly respond to specific email questions so please watch for your answer in the column.  Email your questions for the column to This e-mail address is being protected from spambots. You need JavaScript enabled to view it and watch for your answer.

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