Cataracts

What is a cataract?

Inside the eye there is a lens which focuses light entering the eye on to the retina which is the light sensitive surface at the back of the eye. This is very similar to a camera which has a lens to focus light onto the film (or light sensitive surface in the case of digital cameras!). Normally the lens is transparent. If the whole or part of the lens within the dog’s eye becomes opaque this is called a cataract.

What causes cataracts?

Some cataracts are the result of injury or diseases such as sugar diabetes. Some appear to occur spontaneously and are age related. However in the dog by far the greatest number of cataracts are inherited.

Are some breeds more prone than others?

Many breeds of dogs are affected with hereditary cataracts, among these are the American Cocker, Labrador Retriever, Poodle, Boston Terrier and Staffordshire Bull Terrier to mention just a few. As dogs are living to an older age, senile cataracts are becoming more prevalent.

Will my dog go blind?

If cataracts occupy less than 30% of the lens or only one lens is affected they will often go unnoticed by the dog. When the opacity is affecting about 60% of the total lens area, vision impairment is usually apparent.  If the opacity progresses to 100% of the lens the dog is then unable to see. Whether the cataract remains static or progresses depends on the type of cataract, breed and other factors.

Can anything be done to prevent my dog from going blind?

If the lens is sufficiently opaque to impair vision it can be removed by specialist surgical techniques. Following this operation of lendectomy the dog has a good chance of seeing again but the outcome cannot be guaranteed.

How old will my dog be if he does go blind?

Since the major cause of cataract is hereditary, cataract progression varies from breed to breed. In some breeds cataracts will develop relatively early in life, and vision can be lost at a young age. However, in other breeds, the first signs are detected when the dog is several years old and progression and can be very slow such that affected dogs retain reasonable sight well into old age.

If the condition is hereditary, can nothing be done to prevent it being passed on?

This is a situation where prevention is better than cure. In Australia eye disease certification can be performed by registered specialists and offers breeders an excellent chance to make sure they are producing puppies from disease free stock. Similar schemes are in operation world wide.  In addition, genetic tests may be available for some inherited forms of cataract. We will be more than happy to discuss details with you.