Cataracts in Dogs

A cataract is a clouding of the eye lens that can cause partial or complete vision loss. It may occur in one or both eyes and is fairly common in dogs, especially dogs of certain breeds. These breeds include the Smooth Fox Terrier, American Cocker Spaniel, Bichon Frise, Havanese, Silky Terriers, Miniature and Standard Poodles, Miniature Schnauzers, and Boston Terriers. The cloudiness results from failure of the eye to maintain proper lens hydration. The clouded lens then prevents the retina from receiving light and creating an image. Untreated cataracts can worsen and lead to painful ocular inflammation, glaucoma and/or permanent blindness. Cataracts result in the clouding or darkening of the lens in an eye. Deriving from an increased amount of proteins accumulating in the eye, the lens becomes cloudy or opaque. Cataracts are one of the most common eye problems in dogs. A skilled veterinarian will be able to identify a cataract, which is sometimes confused with nuclear sclerosis.

Cataracts can occur at any age and may be observed in one or both eyes. Symptoms include:

• White “cloudy” appearance in the eye
• Grey/light blue/abnormal coloration in the eye
• Abnormal appearance in light reflection on the eye

Symptoms of vision loss include:

• Bumping into door frames
• Bumping into furniture
• Barking at inanimate objects
• Clumsiness
• Difficulty finding toys or bowls
• Walking with caution
• Walking with nose to the ground

Types

• Congenital cataracts – Cataracts present at birth. Usually in both eyes. Can be inherited or caused by infections or toxins.
• Early onset cataracts – Develop before 3 years of age. Can be inherited or caused by infections, toxins, diabetes mellitus or trauma to the eye.
• Late onset cataracts – Develop at or after 6 years of age. Often confused for nuclear sclerosis (normal clouding of the eye due to aging).

The most common cause of cataracts in dogs is inheritance. Dog breeds genetically predisposed to cataracts include (but are not limited to) miniature and standard poodles, cocker spaniels, miniature schnauzers, golden retrievers, boston terriers, havanese, bichon fries and silky terriers.

Other causes of cataracts in dogs include:

• Diabetes mellitus
• Eye trauma
• Aging
• Uveitis
• Hypocalcemia
• Radiation exposure
• Toxin exposure

If you observe symptoms of cataracts or vision loss in your pet, schedule an appointment with a veterinarian. The veterinarian will want to know when the symptoms were first noted, if any trauma to the eye or head has occurred and if your pet has been behaving differently.

A complete ophthalmologic examination will determine if your pet is experiencing vision loss, is developing true cataracts or if the pet has nuclear sclerosis. Nuclear sclerosis is much more common than cataracts and has similar symptoms to cataracts. This condition is a normal change in the lens of the eye (often both eyes) seen with aging and does not cause significant vision loss or require treatment.

Since cataract development is often seen with diabetes mellitus, a complete blood profile and urinalysis may be ordered to rule out this disease.

The only treatment for cataracts is surgery. Some pets are not good candidates for surgery and your veterinarian will let you know if surgery is a good option. Pets with diabetes or other chronic illness and older pets are not often good candidates for cataract surgery. Healthy pets with hereditary cataracts are good candidates.

If your veterinarian decides your pet should have surgery, it is best to schedule as soon as possible to prevent further damage to the eye. Cataract formation is progressive and can lead to painful inflammation of the eye, glaucoma or complete blindness.

Lens Removal

The lens is removed from its surrounding capsule in the eye globe. The lens is then replaced with a plastic or acrylic intraocular implant.

Lens and Capsule Removal

Both the lens and surrounding capsule are removed from the eye globe. The lens is then replaced with a plastic or acrylic intraocular implant.

Phacoemulsification

In this surgery, the eye lens is emulsified using ultrasonic waves. The emulsified lens is removed through aspiration and replaced with an isotonic solution.

Cataract surgery is a low-risk surgery and has more than a 90 percent success rate in dogs. After surgery, your pet will need to wear an Elizabethan collar (“e-collar” or “cone”) to prevent rubbing the eye on the floor or with the paws. Eye drops or ointment will be prescribed to be applied 2-3 times daily for 3-4 weeks. Pain medications and oral antibiotics may also be prescribed.

After your pet has had cataract surgery, frequent follow up appointments are necessary to evaluate healing and recovery. Your pet should fully recover within 2-3 months.

There is no preventative measure for cataracts, however carefully monitoring your dog’s vision and noting any changes in behavior or the appearance of the eye is a good way to catch cataracts early. The earlier a problem is noted, the more quickly it can be addressed and the more likely vision loss or other health problems will be avoided. Always let your veterinarian know if you have any concerns about your pet’s eyes or vision.