Cataract [Cloudiness of the Lens of the Eye]
Learn what the condition is, how it may be detected early, how it is treated or managed, and which breeds or species are linked to it.
Condition snapshot
A concise guide to the condition’s pattern, detection, management and urgency.
This snapshot is a general guide, not a diagnosis or treatment plan. New, severe or worsening signs require veterinary assessment.
About the condition
A cataract is an opacity within the lens of the eye that prevents light passing through normally. The lens should be transparent so that a clear image can be focused on the retina. Cataracts can affect a small part of the lens or eventually involve it almost completely, and they may develop in one or both eyes. Inherited cataracts are common in dogs and often affect both eyes, although the age at onset and rate of progression vary greatly between breeds.
Cataracts present at or soon after birth are described as congenital, while those developing in young dogs are often called juvenile cataracts. Others appear during adulthood. Not every cataract in an older dog is inherited; diabetes mellitus, inflammation inside the eye, trauma and other ocular disease can also cause lens opacity. Cataract should also be distinguished from nuclear sclerosis, a normal age-related change that gives the lens a grey-blue appearance but usually does not significantly reduce vision.
A small or slowly progressing cataract may cause little functional impairment. As opacity increases, the dog can develop blurred vision, hesitate in dim or unfamiliar environments, bump into objects or become blind in the affected eye. Cataracts can also cause secondary inflammation within the eye, which may be painful and can contribute to complications such as glaucoma or lens instability.
The veterinarian also considers whether an underlying systemic disease is responsible. Many dogs with visually significant cataracts can regain useful vision through surgery. The best outcome depends not only on removing the cloudy lens but also on confirming that the retina and other structures of the eye are capable of supporting vision.
Early evaluation also allows timely discussion of whether surgery is suitable before secondary complications reduce the chance of a successful result.
Screening & Early Detection
Inherited cataracts may be detected before an owner notices any change in vision, so regular eye examination is important in breeds with a recognised predisposition. Puppies from high-risk breeds may undergo an early ophthalmic examination, followed by repeat assessment during adulthood because some inherited cataracts do not appear until several years of age. Breeding programs often use examination by a veterinary ophthalmologist rather than relying on a normal-looking eye.
Screening involves examination of the lens and the rest of the eye, usually with the pupil dilated. The ophthalmologist records the location, size and appearance of any opacity because these features can help distinguish inherited patterns from other causes. Where a validated DNA test exists for a particular breed and cataract mutation, genetic testing can complement clinical examination, but it does not replace eye checks for cataracts caused by other genes or acquired disease.
Seek assessment if a lens appears cloudy, the dog becomes hesitant on stairs, misjudges objects, startles easily or develops redness, squinting or eye pain. Blood glucose testing may be appropriate when cataract appears suddenly or diabetes is suspected. A rapidly developing cataract deserves prompt attention because associated inflammation can begin before complete vision loss.
Diagnosis requires an eye examination, ideally after the pupil has been dilated so the lens can be assessed fully.
Treatment & Management
The only treatment that can restore transparency to a lens with a mature cataract is surgery. The standard procedure uses phacoemulsification to break up and remove the cloudy lens material, usually followed by placement of an artificial intraocular lens to improve focusing. Before surgery, a veterinary ophthalmologist assesses the cornea, retina, eye pressure and general health of the dog. Additional tests such as ocular ultrasound or retinal function testing may be needed when the cataract prevents a direct view of the back of the eye.
Timing matters. Surgery is often easier and outcomes can be better before a cataract becomes very advanced or causes significant lens-induced inflammation. Anti-inflammatory and other eye medications may be prescribed before or after surgery, but drops cannot dissolve an established cataract. Dogs with diabetes require coordinated management of their systemic disease as well as their eyes.
Post-operative care is intensive for a period and usually includes several eye medications, protection from rubbing, controlled activity and scheduled ophthalmic rechecks. Potential complications include inflammation, pressure changes, retinal detachment or infection, although many appropriately selected dogs achieve useful vision.
When surgery is not performed, management focuses on monitoring comfort and treating inflammation or secondary glaucoma if it develops. Blind dogs can adapt remarkably well in a stable environment, but a blind eye should still be examined if it becomes red, enlarged, cloudy or painful. Preserving comfort is always important, even when vision cannot be restored.
Breeds or species affected
Affenpinscher
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Afghan hound
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Akita
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Alaskan malamute
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American Cocker Spaniel
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Australian Cattle Dog
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Australian shepherd
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Basenji
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Beagle
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Bearded collie
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Bedlington terrier
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Belgian Shepherd Dog (Groenendael)
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Belgian Shepherd Dog (Tervueren)
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Bernese mountain dog
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Bichon frise
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Black Russian Terrier
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Border Collie
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Border terrier
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Borzoi
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Boston terrier
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Bouvier des Flandres
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British Bulldog
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Brussels griffon
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Cairn terrier
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Cavalier king charles spaniel
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Chesapeake Bay retriever
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Pug
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Shar Pei
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Chow chow
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Clumber spaniel
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English Cocker Spaniel
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Collie
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Collie (rough & smooth)
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Curly-Coated Retriever
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Dachshund
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Dalmatian
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Dobermann
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English Pointer
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English springer spaniel
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English toy spaniel
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Entlebucher mountain dog
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Flat-coated retriever
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Smooth Fox Terrier
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Wire Fox Terrier
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French bulldog
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German shepherd
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German shorthaired pointer
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German Wirehaired Pointer
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Golden retriever
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Gordon setter
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Great Dane
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Harrier
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Havanese
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Ibizan hound
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Irish setter
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Irish water spaniel
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Irish wolfhound
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Italian greyhound
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Jack Russell Terrier
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Japanese Chin
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Keeshond
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Kerry blue terrier
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Komondor
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Kuvasz
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Labrador retriever
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Lakeland terrier
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Lhasa apso
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Lowchen
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Manchester terrier
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Mastiff
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Miniature Pinscher
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Miniature Poodle
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Miniature Schnauzer
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Neapolitan mastiff
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Newfoundland
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Norfolk terrier
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Norwegian buhund
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Norwegian elkhound
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Norwich terrier
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Nova Scotia duck tolling retriever
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Old English sheepdog
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Papillon
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Parson russell terrier
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Pekingese
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Pembroke Welsh Corgi
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Pomeranian
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Poodle (standard)
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Portuguese water dog
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Puli
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Retriever (flat or curly coated)
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Rhodesian ridgeback
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Rottweiler
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St Bernard
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Samoyed
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Schipperke
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Schnauzer (miniature, standard)
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Schnauzer (standard)
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Scottish terrier
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Sealyham terrier
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Shetland sheepdog
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Shih tzu
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Siberian husky
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Silky terrier
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Soft coated wheaten terrier
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Springer spaniel
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Staffordshire bull terrier
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Sussex spaniel
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Tibetan spaniel
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Tibetan terrier
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Welsh corgi
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Welsh springer spaniel
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Welsh terrier
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West Highland white terrier
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Whippet
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Yorkshire terrier
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