Understanding and Treating Cataracts in Dogs
Is Fluffy bumping into objects, tripping over curbs, or missing stairs? Does she struggle to recognize familiar people or items? If so, it’s time to visit the vet to have her eyes checked.
As dogs age, a natural bluish-grey cloudiness called Nuclear Sclerosis often develops in the lens of the eye. This normal condition, caused by the hardening of the lens, affects close-up focus but doesn’t impair distance vision.
Cataracts, however, are a different issue. Though not common, their incidence is increasing. Conditions like diabetes mellitus raise the risk, and certain breeds, such as the Miniature Schnauzer, Cocker Spaniel, Siberian Husky, Labrador, and Golden Retriever, are more prone. Other causes include eye trauma, inflammation, and milk replacers, often seen in bottle-fed orphaned puppies.
A cataract is a white opacity within the eye’s lens, severely affecting both near and far vision. Despite appearing as a surface film, cataracts form deep within the lens, behind the iris and pupil. They result from an imbalance in the lens’s nutrients (normally 33% protein and 66% water), where increased water and insoluble protein create cloudiness, reducing lens transparency.
Some cataracts remain small (incipient cataracts), common in retrievers, and may not require surgery. More often, they progress to immature cataracts, partially blocking vision, and eventually mature cataracts, causing full blindness.
Treating Cataracts in Dogs
The cause, timing, and type of cataract are critical for developing a treatment plan. Congenital cataracts, present at birth, are often hereditary but can also result from toxins or infections in the uterus. Developmental or Early Onset Cataracts may stem from hereditary traits, diabetes, trauma, infections, or toxins. Senile Cataracts appear in dogs over six years old due to aging.
Dogs with congenital or developmental cataracts should be removed from breeding programs and spayed or neutered immediately. All breeding stock should pass a Canine Eye Registry Foundation test by an ophthalmologist to catch congenital conditions before they’re passed on.
Early diagnosis and treatment improve the chances of restoring much of a dog’s original eyesight, though it won’t match their youthful vision. Conventional treatment typically involves surgical removal of the cataract. Untreated cataracts can lead to Lens Induced Uveitis (LIU), an inflammatory condition requiring lifelong anti-inflammatory drops to prevent complications like detached retinas or glaucoma, which may cause blindness and necessitate eye removal. LIU reduces the success rate of cataract surgery, underscoring the need for early intervention.
Cataract surgery, despite some risks, has a high success rate with proper postoperative care. For weeks before and up to six weeks after surgery, eye drops must be administered multiple times daily, along with regular checkups with your veterinarian or ophthalmologist.
The most common procedure, phacoemulsification, involves a small incision and an ultrasonic probe to break up and remove the cataract, similar to human cataract surgery. Less commonly, extracapsular cataract extraction removes the entire lens. A new lens is often fitted to improve focus; without it, the dog will be farsighted, with optimal vision between three and fifteen feet.
Over the past two decades, studies in Russia and China have found N-acetylcarnosine to be an effective treatment for senile cataracts. Though not yet FDA-tested, it’s available in the U.S. and safe for both humans and dogs, offering an 80–90% improvement in cataract density. While not a complete alternative to surgery, it may soon be viable for cases where surgery isn’t recommended.
Despite the challenges of cataracts, dogs can lead normal lives post-surgery, even with reduced focus range. You may need to guide them with a “careful” command around stairs or obstacles, but this is little different from supporting an aging dog. Teaching a “careful” command is useful at any age, as even dogs with perfect vision can misjudge a ledge or encounter hazards during exuberant play.
