Nearly every day, a client will say, “Doc, I think my dog has cataracts.”

The reason for such a common concern in veterinary practices is older dogs will begin to develop cloudy eyes. Most of the time, though, the cloudy eyes are not cataracts.

Nuclear sclerosis is the normal aging process in which the lens inside of the eye becomes somewhat cloudy. This is the condition responsible for many dog owners believing their dog has cataracts.

Nuclear sclerosis generally does not cause complete blindness.

The natural aging changes of nuclear sclerosis cause the lens to become cloudy without developing into a solid opacity as seen with cataracts. A dog’s vision is affected by nuclear sclerosis, but only to the point of decreased sharpness of vision.

Cataracts are the most common cause of blindness in dogs.

Cataracts are the condition of the eye when the lens becomes opaque.

The lens is the structure inside the eye which focuses light on the back of the eye called the retina. Vision occurs at the retina.

Cataracts cause blindness whenever the entire lens becomes opaque and does not allow for light to pass through to the retina.

Typically, visual impairment begins when the opacity covers about 60 percent of the lens.

The most common cause of cataracts in dogs is inherited cataract formation. Cataracts generally are age-related, only developing in older dogs. Other causes of cataracts include eye injuries and diabetes.

It is common for diabetic dogs to develop cataracts. However, the quicker the diabetes is diagnosed and treated, the less likely cataracts will develop.

Genetic predisposition occurs in certain breeds such as cocker spaniels, labrador retrievers, poodles, Boston terriers and Welsh corgi.

Any breed of dog, even mixed breeds, can develop cataracts as they get older or become ill with certain conditions, though.

Many dog owners may think their dog has cataracts when actually they just have nuclear sclerosis. That’s why it is important to have your dog’s eyes examined by your veterinarian to determine whether they have a problem with cataracts or just have normal aging changes.

Your dog should receive their vaccinations once a year which is a good time for them to have their eyes evaluated as well.

If your dog’s cataracts are simply due to heredity, the age of development and rate of progression can vary greatly.

Some dogs may develop cataracts at an early age, yet the majority of genetically-prone dogs usually don’t begin to have cataracts until their geriatric years.

It is not unusual for diabetes to affect dogs in their middle ages — around 5 to 7 years old — which causes cataracts at an earlier age than normal.

It is not recommended to breed a dog that has been determined to have hereditary cataracts. These dogs are likely to produce at least some of the litter that would also have hereditary cataracts.

Unfortunately, it is nearly impossible to determine if a puppy has hereditary cataracts from examining their eyes when they are young and before any cataract development. But, some breeders will actually have their breeding stock certified to be free of any eye diseases.

As always, prevention is much better than a cure.

Surgical removal of the affected lens containing the cataract is the only means of properly treating them.

Surgical removal of cataracts requires a veterinary specialist, or ophthalmologist, to perform the extremely difficult procedure.

If you choose to have your dog’s cataracts removed, your veterinarian can arrange a referral appointment to an ophthalmologist to further evaluate your pet’s condition.

If you think your dog has any kind of eye problems, contact your veterinarian as soon as possible to ensure your dog lives a long, healthy, and happy life.

Dr. Jeff Castle is a veterinarian at Clark County Veterinary Clinic.