Cataracts are one of the most common eye problems in dogs, and they show up in canines of all breeds and in animals both young and old. As with humans, the only successful treatment is surgery.
The word "cataract" literally is Latin for "break down," and refers to a problem that develops with the fibers in the lens of the eye. The disruption of these fibers causes the lens to become cloudy, reducing vision. There are several types of cataracts, which have different causes. All, however, result when the biochemistry of the eye (66 percent water and 33 percent protein), becomes out of balance. The end result is that too much water remains in the lens of the eye, while the percentage of insoluble proteins increases. The combination causes the cloudy white coating, loss of transparency and loss of vision characteristic of cataracts.
How old a dog is when the cataract develops is a significant clue to diagnosing what type it is. Congenital cataracts are present at birth, and are caused by toxins or infections developed in utero. In rare cases, especially in Miniature Schnauzers, this type of cataract also can be genetically inherited.
Developmental, or Early Onset, cataracts occur early in the dog's adult life. They may also be inherited or caused by an injury, infection, toxin and diseases like diabetes. Inherited cataracts in younger dogs are more common in certain breeds, and dogs who exhibit these inherited cataracts should not be bred.
Finally, dogs over age six frequently develop Senile, or Late Onset, cataracts. At this age, often dogs do not have cataracts, but instead have a more common condition known as "nuclear sclerosis," which produces a graying of the eye's lens. This is a normal age-related change that occurs in dogs, usually by the time they're six years old, and appears in both eyes. It does not affect the dog's vision, and thus is usually left untreated.
Many breeds of dogs are prone to inherited cataracts or early development of cataracts. They include the: Afghan Hound, American Cocker Spaniel, Boston Terrier, Chesapeake Bay Retriever, German Shepherd, Golden Retriever, Labrador Retriever, Miniature Schnauzer, Old English Sheepdog, Siberian Husky, Staffordshire Bull Terrier, Standard Poodle, Welsh Springer Spaniel and the West Highland White Terrier.
Treatment for canine cataracts is the same as that for humans - surgical removal of the eye's lens. It's a procedure that's being done far more often in dogs, with about a 95 percent success rate. Animals who are not good candidates for cataract surgery include dogs who are aggressive, have uncontrolled diabetes, or are in poor or failing health.
Pet owners who do choose to have their dog's cataracts removed must be prepared to spend a significant amount of time caring for their pet post-op. Prescription eye drops must be administered several times a day for several weeks before the procedure, and for about six weeks afterward. Post-operative checkups also are required the day after surgery, and at one-week, three-week and six-week intervals.