What this means
A spot on the eye may appear as a white or silvery shining place, a milky cloudy patch, or a darkened or pinkish area on the clear surface of the eye. It can be small or large, single or several, in one eye or in both. Sometimes the dog does not seem to feel it, and sometimes the eye hurts, waters or is rubbed.
Changes on the clear surface of the eye have very different causes: inherited changes in the cornea, hairs growing from the edge of the eyelid, dry eye, inflammation caused by the immune system, changes in the fats in the blood, or damage after an injury. The cause cannot be told from the look of the spot, and some spots can in time disturb sight. That is why a spot is worth showing to a vet rather than waiting.
Eye problems can quickly harm sight. If the spot appeared suddenly, if the eye is sore or red, if your dog is squinting or the cloudiness spreads fast, go the same day. Do not put any drops in the eye or use home remedies. Your vet will find it useful to know when you noticed the spot, whether it is growing, whether it is in both eyes and, if you can, a photograph of the eye in daylight.
Possible causes
These are things that can cause this sign. It is not a diagnosis, and they are not equally likely for your dog.
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An inherited change in the cornea
In some dogs deposits build up in the cornea, giving a white or silvery patch. It is often in both eyes.
About the condition: Corneal dystrophy -
Extra or misplaced hairs on the eyelid edge
If hairs grow from the edge of the lid and rub on the eye, they can irritate its surface and a cloudy patch can appear on the cornea.
About the condition: Distichiasis -
Too few tears
When the eye is not kept moist enough, its surface dries, clouds or darkens. The dog may rub the eye or blink more.
About the condition: Dry eye (keratoconjunctivitis sicca) -
Immune-related inflammation of the cornea
Pinkish or dark tissue creeping slowly in from the edge of the eye can cover the surface of the cornea and in time worsen sight.
About the condition: Pannus (chronic superficial keratitis) -
Changes in the fats in the blood
When there is too much fat in the blood, milky patches can appear in the eyes. Other signs, such as digestive upsets, sometimes appear too.
About the condition: High cholesterol (hyperlipidaemia)
What else to watch for
These observations help your vet build the picture faster. Note down what you saw and when.
- What colour the spot is and where on the eye it sits
- Whether the spot is growing or changing colour
- Whether the change is in one eye or both
- Whether the eye is watering, red or has discharge
- Whether your dog squints, rubs the eye or avoids light
- Whether your dog sees as well as before
When to book a routine visit
A spot on the eye is worth showing to a vet, and if it appeared suddenly or the eye hurts, go the same day, as eye problems can quickly threaten sight. Put nothing in the eye.
Related conditions
Conditions whose entries mention this sign. The list is somewhere to read on, not a way to reach a diagnosis.
- Corneal dystrophy Eyes Corneal dystrophy is an inherited condition in which fat or mineral deposits build up in the clear cornea of the eye, or its cells stop working properly, so the cornea becomes cloudy in places. It can be entirely painless and affect vision little, but some forms can cause the cornea to swell or develop small ulcers. A vet assesses the changes and follows how they develop.
- Distichiasis Eyes Distichiasis is a condition in which extra eyelashes grow from the edge of the eyelid, where no lashes should be. Soft lashes may barely bother the eye, but stiffer ones rub against its surface. Constant rubbing irritates the eye and can damage the cornea, so whether the lashes are causing harm is for a vet to judge.
- Dry eye (keratoconjunctivitis sicca) Eyes Dry eye is a condition in which the tear glands make too few tears, so the cornea and the conjunctiva dry out and become inflamed. Without its protective tear film the eye becomes sore, and over time the cornea can darken, scar and lose its clarity. This can weaken eyesight, so changes are worth showing to a vet.
- High cholesterol (hyperlipidaemia) Hormones and metabolism Hyperlipidaemia is a condition in which there is too much fat in the blood, such as cholesterol or triglycerides. It can be inherited or caused by other diseases such as hypothyroidism, diabetes or kidney disease, so it matters to find out what lies behind it. High levels of fat in the blood can contribute to inflammation of the pancreas and to changes in the eyes and other organs.
- Pannus (chronic superficial keratitis) Eyes This is an immune-related inflammation of the cornea: pinkish tissue that later darkens creeps slowly from the edge across the clear surface of the eye, like a cloud across a window. It develops slowly and may not hurt at all, so it is easy to miss, but over time it can impair vision. Only a vet can diagnose it and follow how it progresses.
Body systems: Eyes Hormones and metabolism