Health
A bluish sheen in the eye, a halt at the top of the stairs, a pearly spot in the pupil. Not every cloudy eye is a cataract, and not every cataract ends in blindness.
Caution. A red, painful eye he keeps shut, one eye that looks bigger, a cornea that suddenly turns blue-grey, blindness over a day or two, or a white eye that appeared quickly in a dog who drinks a lot: see your own vet the same day.
Do not look for the answer in a Facebook group, on TikTok or on a forum. Look for someone trained for this: your dog's own veterinarian, the only person who can examine, investigate and treat them.
Use this page to know what to observe, what to note and what to ask at the appointment, not to treat at home. If you still have doubts after a consultation, ask another vet or a specialist (dermatologist, internist) for a second opinion, not a group. And if you do not have a regular vet yet, find one now, while your dog is healthy: how to choose a veterinary clinic.
You notice it one evening under the kitchen light: a bluish sheen in your dog's eyes that was not there before. Or your nine-year-old has walked into the table leg twice this week and stopped dead at the top of stairs he has climbed all his life. Or your two-year-old has a pearly white spot right in the middle of the pupil. All three owners end up asking the same thing: is it a cataract, and is he going blind? The answer varies a lot from dog to dog. A bluish eye in an older dog is usually an age change he sees through almost normally. A white spot that keeps growing is a different matter. Treatment is your vet's call, often together with a veterinary eye specialist; your part is spotting what is urgent, keeping useful notes and making life easier for the dog.
A cataract does not hurt and will not have you driving to the clinic at midnight. Some conditions that look like it, or grow out of it, will. Call today if you see:
Behind these can be glaucoma (high pressure inside the eye), a luxated lens (the lens slipping out of place) or inflammation inside the eye. Glaucoma can destroy sight in hours. Phone, describe exactly what you see, and if your vet has no equipment to measure eye pressure, they will send you to someone who does.
Behind the pupil sits the lens, normally crystal clear. A cataract is that lens turning cloudy and then white, rather like egg white in a hot pan. Less and less light gets through. First the dog sees as if through a steamed-up window, then not at all.
The confusion comes from a second change that nearly every dog over 7 or 8 gets, and which looks much the same to an untrained eye: nuclear sclerosis. The lens hardens with age and goes slightly hazy. The eye looks bluish and milky, especially in flash photos. The dog sees almost normally and needs no treatment at all.
| What you see | Nuclear sclerosis (age) | Cataract |
|---|---|---|
| Colour | Even blue-grey, like smoke | Chalky white, sometimes with spots or lines |
| Both eyes | Almost always, equally | Often, but one tends to go first |
| Age | Over 7 or 8 | Any age, including puppies and young dogs |
| Sight | Almost normal | Gets worse, from hesitating to blindness |
| Speed | Years | Months, or weeks with diabetes |
Use the table as a rough guide. The vet makes the call, and can tell the two apart in seconds with a light and a magnifier.
Put an empty box in his usual route through the house and watch whether he steps round it early or bumps into it. Try it once in daylight and once in the evening with the lights low. Plenty of dogs with early cataracts manage fine in sunshine and get lost at dusk.
Toss a ball of paper or a cotton wool pad across his line of sight, without a sound. A sighted dog follows it with his eyes.
Do not flick your hand at his face to see whether he blinks. He feels the air move and blinks anyway, so it tells you nothing.
When you first saw the white, and in which eye. Whether it has grown. How he moves around the house, on the stairs and in the park, by day and by night. Whether he is drinking more: for a few days, measure what goes in the bowl in the morning and what is left at night. Any weight loss, any knock to the head or eye. His breed and, if you know, whether his parents or littermates had eye problems.
Once a month, photograph his eyes in natural light, straight on and slightly from the side. No flash: with flash almost any dog's eye comes out white or green and you have nothing to compare.
Before you leave, ask three things: how fast it is growing, which signs of pain mean coming straight back, and when the next check-up is.
Dogs cope with losing their sight far better than we fear. Their world is built mostly from smell and sound. Help him with a mat of a different texture at the top of the stairs and by the door, a few simple words you always use ("careful", "step", "wait"), a bell on the other dog's collar and a scent dabbed on dangerous corners. Outside, a long line and the same route.
On the trail we see it again and again: the eyes go, the nose stays exactly as it was. Treats hidden round the house or a short track through grass are things he can do as well as he ever did. And an old dog who has found what he was looking for on his own is a different dog for the rest of the day.
What dog owners search for most often on the internet about this problem, with the short answer. The answers are a guide only: the decision belongs to your dog's own vet, after an examination.
In a dog over 7 or 8 it is usually nuclear sclerosis: the lens hardens with age and turns bluish, and he sees almost normally. A chalky white with spots that dims his sight is a cataract. Less often the cloudiness sits on the surface of the eye (the cornea), from inflammation, an injury or glaucoma. A vet can tell which in minutes with a light and a magnifier.
It depends how fast it grows. Some cataracts stay small for years and barely bother him. Others, diabetic ones in particular, lead to blindness within weeks. Once the lens is completely white he can only tell light from dark. Regular check-ups show the pace, and your vet will say whether surgery is worth talking about.
Yes. A veterinary eye specialist breaks up the cloudy lens with ultrasound, removes it and usually fits an artificial one. First they check that the retina still works, otherwise surgery will not bring sight back. Afterwards come weeks of drops, a cone and check-ups, so how well your dog tolerates handling matters too.
High blood sugar changes how the lens draws in water, so it swells and turns white, sometimes within weeks. Most diabetic dogs develop cataracts within the first year after diagnosis. So a white eye that appears quickly in a dog who drinks and pees a lot needs blood tests as well as an eye check.
Keep the furniture where it is, put a textured mat at the top of the stairs, speak before you touch him and use the same simple words for "careful" and "step". Outside, a long line and familiar routes. His nose is as good as ever, so search games and short tracks give him back a joy his eyes no longer can.
The information on this page is educational and does not replace an examination. For full details and a diagnosis, consult your dog's own veterinarian.
They often come together: the same causes, plans that complement each other.
A red eye, watering, brown gunk in the morning, one eye held shut. Conjunctivitis is the word that springs to mind; often it is something else, and eyes do not wait.
The water bowl is empty by lunchtime, she wakes you at night to go out and loses weight though she eats everything. Diabetes is for life, but very manageable.
He paces at night, stands with his nose in a corner, waits at the wrong side of the door, wees indoors. Some of it is age. Some of it can be treated.
He no longer comes when you call from the kitchen and jumps when you touch him asleep. Often it is not old-age stubbornness at all: he simply cannot hear you.
We work with your dog's behaviour, not its health. For any sign described here, book an appointment with your own vet; the related services page explains how to choose a clinic.