White spots on dogs’ eyes are not normal. They can be harmless, such as mucus, or they can be serious eye conditions. The most common conditions for white spots are cataracts, glaucoma, eye injuries, corneal ulcer, and others. Contact your veterinarian for a correct diagnosis and appropriate treatment.
Most owners, when they talk about pet medical emergencies, think of car accidents, poisoning, attacks by other animals, and so on.
These are obvious circumstances that are quickly identified.
But pet owners must know that in addition to these obvious emergencies, there are other subtle dangers that can endanger the dog’s health and life.
While these spots can be insignificant (as with mucus), they can also be dangerous (such as a corneal ulcer).
In this article, you will learn why dogs have white spots on their eyes, the causes, what you need to do, and more.
Why Does My Dog Have a White Spot on His Eye?
Dogs should not have white spots on their eyes. These are most often the result of a medical condition. The condition can take place outside or inside the eye. In some cases, a white spot on the dogs’ eyes is caused by harmless mucus.
Dogs’ eyes should be clear, with a smooth surface, and without spots.
Symptoms of eye problems generally include:
- Red conjunctiva
- They are dry or watery
- They show damage on the surface
- They are cloudy
- They have white spots
White spots on dogs’ eyes generally appear as a result of medical conditions, which often represent one of the following medical emergencies:
- Cataracts
- Nuclear sclerosis
- Glaucoma
- Cholesterol deposits on the cornea
- Corneal ulcer
- Corneal endothelial degeneration
- Uveitis

White Spot on My Dog’s Eye or Mucus?
Dog owners sometimes confuse the mucus on the eyes with true white spots. It appears as a white or yellowish film on the eye that moves when dogs blink. It does not represent an emergency.
Mucus (eye secretions) itself is not a medical condition. But it can be a symptom of an eye condition.
It most often occurs because of dust or dry eyes. It is harmless and can be removed by you with a clean cloth.
The mucus appears as a white, yellow, or greenish-yellow irregular spot. Unlike medical conditions where the white spots on the eyes are motionless, mucus moves around when the dog blinks.
Take your dog to the vet if it produces eye secretions excessively.
White Spots on Dogs’ Eyes Caused by Cataracts
Cataracts in dogs give the sensation of white spots on dogs’ eyes. It is not located on the surface of the eye, but inside the eye where it affects the lens. Cataracts cause the eyes to have a cloudy-white appearance. It occurs for several reasons, including diabetes and old age.
Cataract refers to the clouding of the lens of the eye. This varies from partial coverage to complete coverage.
When this clouding of the lens of the eye occurs, it prevents the passage of light to the retina, causing vision loss.
Most cases of cataracts are hereditary and certain breeds[1] are predisposed to developing it:
- Miniature poodle
- Cocker spaniel
- American Cocker Spaniel
- Miniature Schnauzer
- Golden retriever
- Boston terrier
- Siberian Huskies
Cataract symptoms are usually related to the degree of deterioration of vision caused by the condition:
Dogs with less than 30% eye damage do not show too obvious symptoms. Dogs with more than 60% eye damage show the following symptoms:[2]
- Your dog often bumps into objects.
- It gets easily scared.
- Poor depth perception.
- Cloudy eye appearance.
This can affect one eye or both eyes.

Although most cases of cataracts are hereditary, there are other causes that can lead to this condition:
- Diabetes
- Old age
- Electric shock
- Inflammation of the uvea of the eye (uveitis)
- Hypocalcemia
- Exposure to radiation and toxic substances
White Spots on Dogs’ Eyes Caused by Nuclear Sclerosis
Nuclear sclerosis is often confused with cataracts. The difference is that it does not affect vision, as in the case of cataracts. Affected eyes have a cloudy-bluish appearance that can give the sensation of white spots on the eyes.
Nuclear or lenticular sclerosis is an opacification of the lens nucleus. It does not affect dogs’ vision. This condition is caused by old age, which is why it’s only seen in old dogs.[3]
The vet can identify whether your dog is affected by nuclear sclerosis or cataracts.
White Spots on Dogs’ Eyes Caused by Glaucoma
Glaucoma can give the sensation of white spots on the eyes because it gives them a cloudy-white appearance. It can lead to permanent blindness if not diagnosed and treated in time.
The eyes contain a liquid inside that helps them maintain their shape. Glaucoma is a medical condition where the pressure inside the eye increases beyond normal limits.
High pressure can damage the retina and the optic nerve. In the worst of cases, it can lead to permanent blindness.

Here are the first signs of glaucoma:
- Pain (pawing at the affected eye, dogs rub their heads on different objects)
- Cloudy eyes
- Thickened blood vessels in the white part of the eye (sclera)
- Dilated pupils
Most dogs only show 1-2 of these symptoms.
There are two types of glaucoma:[4]
- Primary
- Secondary
Primary glaucoma is caused by genetic factors, and certain breeds are predisposed to its development:
- Bloodhound
- Cocker spaniel
- Basset hound
This type of glaucoma rarely occurs in both eyes at the same time. It can take years until both eyes are affected.
Secondary glaucoma is not breed-specific and occurs for other reasons:
- Eye wounds.
- Inflammation inside the eye.
- Eye bleeding.
- Movement of the lens of the eye.
- Degeneration of the structure inside the drainage angle or anything that causes the narrowing or closing of this angle.
White Spots on Dogs’ Eyes Caused by Cholesterol Deposits On the Cornea
Cholesterol deposits on the cornea appear as white-gray, opaque, oval, or round spots. These are accumulations of fat formed from cholesterol crystals. The causes of this are hereditary corneal dystrophy, diabetes, and hypothyroidism.
This condition is also called corneal lipidosis or lipid keratopathy. It appears as grayish-white, round or oval spots that develop on the surface of the dog’s eye.
These spots are accumulations of fat and can cause pain and interfere with dogs’ vision.

There are three causes of corneal lipidosis:[5]
- Hereditary corneal dystrophy
- Diabetes
- Hypothyroidism
Some breeds are more prone to the development of this condition:
- Beagle
- Cocker spaniel
- Collie
- Shetland
- Samoyed
- Alaskan Malamutes
- Siberian husky
- Cavalier King Charles spaniel
- Airedale
- Miniature Schnauzer
- Weimaraner
- Bichon
- Whippet
- Mastiff
White Spots on Dogs’ Eyes Caused by Corneal Ulcer
Corneal ulcer is an extremely painful eye problem that needs prompt intervention to avoid complications. It can lead to blindness if not treated in time.
Corneal ulcer is an injury that affects the cornea, the most superficial part of the eye.
There are many causes of Corneal ulcer:
- Trauma, blow, or penetration
- Disease
- Lacrimal deficiency
- Infection
- The impossibility of closing the eyelids completely
- Facial nerve palsy
- Foreign body
- Burns from a chemical substance
- Corneal ulcer symptoms in dogs include:
- Red and painful eye
- Excessive lacrimation
- Photosensitivity
- Rubbing the eyes with the paw
- The affected eye may remain closed
- Secretions
- The film over the eyes gives the appearance of a white spot on the eye or cloudy eyes
Related: Bumps on Dogs’ Eyelid

White Spots on Dogs’ Eyes Caused by Corneal Endothelial Degeneration
Corneal endothelial degeneration generally occurs in old dogs or can be inherited. Initially, it looks like a grayish-white spot in the middle of the eye. It then spreads over the entire surface, giving the eye a white appearance.
Corneal endothelial degeneration is a medical condition in which the internal layer of the cornea degenerates.[6]
It occurs in old dogs or can be inherited in by the following breeds:
- Chihuahua
- Boston terrier
- Dachshund
Corneal endothelial degeneration initially appears as a gray-white spot in the middle of the eye. Over time, it spreads to the entire eye.
It causes blindness as the disease progresses.
White Spots on Dogs’ Eyes Caused by Uveitis
Uveitis is a condition that gives the eye a white, cloudy appearance. The causes of uveitis are multiple, and it can lead to blindness if it is not treated.
The uvea is the dark tissue at the front of the eye that is made up of three distinct structures (choroid, ciliary body, and iris) and contains the blood vessels. Anterior uveitis is the inflammation of this tissue.
In dogs, this condition affects the iris and surrounding pupillary tissue, which in turn can affect their vision.

Symptoms of uveitis in dogs include:
- Pain
- Redness of the eye
- Secretions
- The pupil is unusually small or unevenly shaped
- Swelling of the eyeball
- The front part of the eye is cloudy
- The color of the iris may be uneven or different from normal
Anterior uveitis in dogs can have various causes:
- Autoimmune diseases
- Tumors
- Trauma or injury
- The proteins of the lens that enter the eye fluid
- Infections with parasites, fungi, bacteria, and viruses
When Should I Seek Treatment for My Dog’s White Spots on Its Eyes?
You should seek treatment for the white spots on your dog’s eyes as soon as you notice them. They often lead to eye infections and/or blindness.
Many eye conditions in dogs have similar symptoms. That is why it is recommended to notify your veterinarian as soon as your dog has vision problems. It doesn’t matter if the white spots are small or big.
The vet is the only person capable of doing ophthalmic examinations and detailed measurements. This is necessary to make a correct diagnosis and prescribe an appropriate treatment.
Take your dog to the vet if you notice the following changes in your dog’s eyes:
- Grayish-white spots on the eyes
- Cloudy eyes
- Bleeding
- Excessive secretions
- Pain
- Tearing
- Your dog keeps the affected eye shut
- The dog bumps into objects
Many eye conditions can lead to permanent blindness if they are not treated in time.
Related: Dark Spot on Dog’s Eyes
Signs of Blindness in Dogs
Dogs that go blind slowly can adapt extremely well, and the owner may not even realize something is wrong with their dog.
Instead, dogs that go blind suddenly show the following clinical signs:
- They are disoriented.
- They have difficulties in finding personal things.
- They have fearful behavior.
- They bump into the surrounding objects.
- They refuse to eat.
- They hesitate when walking.
- They can become anxious or clingy.