Cloudy Eyes in Dogs: Why Are My Dog’s Eyes Cloudy?

You may be wondering why your dog’s “windows to the soul”—their eyes—appear to be a little fogged over or hazy.

Cloudy eyes in dogs most commonly develop as a normal part of aging, but there are medical causes for a dog’s cloudy eyes that should be ruled out before assuming there’s nothing to worry about.

What Are Cloudy Eyes in Dogs?

A cloudy dog eye may have a white or blue haze within or on the outer surface of the eye.

While most causes of a cloudy eye are not a medical emergency, some cases are.

If your dog is pawing at their eye or holding it shut, their eye appears swollen or enlarged, or is bleeding, or you’re otherwise concerned, it’s best to contact your veterinarian as soon as possible. Eye issues can cause a significant amount of pain for your pup.

Most Common Causes of Cloudy Eyes in Dogs

Opacities in the eye’s lens, which is behind the pupil, can cause a cloudy appearance.

An abnormality affecting the cornea, the clear outer layer of the eye, can also cause the eye to have a cloudy appearance. 

As we consider the common causes of cloudy eyes in dogs, we’ll focus on three different parts of the eye: the lens, the cornea, and other internal parts of the eye.

Cloudy Eyes Due to Issues With the Eye’s Lens

1. Nuclear sclerosis: Nuclear sclerosis is a normal aging change in dogs. As dogs get older, the eye’s lens becomes denser, causing it to develop a bluish haze.

   1. Nuclear sclerosis in dogs usually develops in both eyes at the same time but doesn’t significantly impact vision.

2. Cataracts: A cataract is an opacity in the lens that prevents light from passing through, affecting vision.

   • Cataracts most commonly develop due to genetics or diabetes. However, some occur spontaneously or with no known cause as a dog ages. If cataracts are not managed and worsen, they can cause blindness.

Cloudy Eyes Due to Issues With the Cornea

1. Corneal ulcers: Corneal ulcers are injuries on the corneal surface that are usually caused by a physical injury or an infection.

   • Typically, a specific part of the cornea appears cloudy rather than the entire structure. Corneal ulcers can be quite painful, so your dog may squint or paw at their eye. You may also notice significant discharge from the eye.

2. Corneal scars: An old injury, such as a corneal ulcer, can leave a scar on the cornea. Corneal scars can look hazy or foggy.

3. Corneal dystrophy: Corneal dystrophy causes the cornea to become opaque or cloudy due to abnormal buildup of materials, such as fat droplets or cholesterol, inside the cornea.

   • Corneal dystrophy is an inherited condition. Most dogs with corneal dystrophy don’t have significant changes to their vision, but some may develop painful ulcers.

4. Corneal endothelial degeneration: This is an age-related, degenerative disease that can cause blindness and pain.

   • As certain cells in the cornea break down, fluid builds up in the cornea (i.e., corneal edema), causing a foggy or blue appearance sometimes called canine blue eye. Small blisters (i.e., bullae) may form on the surface of the cornea and rupture. 

• Dry eye (i.e., keratoconjunctivitis sicca): A dog with keratoconjunctivitis sicca (KCS) doesn’t produce enough tears to keep the eye surface lubricated. This is usually an immune-mediated condition where the body’s immune system attacks the tear-producing glands.

  • Dogs with KCS usually have red, painful eyes and thick, yellow discharge. It’s common for dogs with KCS to develop corneal ulcers and scarring. You may also notice a brown discoloration of the cornea, and the eyes may appear lusterless.

Cloudy Eyes Due to Other Internal Ocular Issues

1. Glaucoma: Glaucoma is increased pressure inside the eye. This is a painful condition, and high ocular pressure can be an emergency.

   • If glaucoma is unmanaged, blindness is likely to occur. Glaucoma can be primary (i.e., inherited) or secondary to another condition, such as cataracts. The eye can appear cloudy or irritated, and it may have a bulging appearance.

2. Anterior uveitis: Anterior uveitis is inflammation of the structures in the front portion of the eye, including the iris.

   • In addition to cloudiness, you may notice redness, discharge from the eye, squinting, or a misshapen iris and/or pupil. Anterior uveitis can develop secondary to infection, cancer, autoimmune diseases, and other conditions.

Should You Go to the Vet If Your Dog’s Eyes Are Cloudy?

If you notice a sudden change in your pet’s eyes or vision, it’s best to contact your veterinarian.

Other signs that your dog needs to see a veterinarian include:

• Discharge from the eye

• Redness of the eye

• Swelling in or around the eye

• Pawing at the eye

• Excessive squinting or blinking

• Changes in vision, indicated by bumping into objects or failure to track a tossed treat

If your dog is in significant pain or their eye appears to be bulging, seek emergency attention.

How Veterinarians Diagnose Cloudy Eyes in Dogs

Your veterinarian will examine your dog’s eyes with an ophthalmoscope, a tool that allows them to see into the back of the eye.

They may assess your dog’s vision by seeing if they blink in response to a hand coming toward their eye (i.e., menace response) and testing if they can track items.

Other tests your vet may run include:

• Schirmer tear test: The veterinarian will place a test strip in your dog’s eye to measure the volume of tears they produce over the course of a minute. This test is used to diagnose dry eye.

• Fluorescein stain test: The veterinarian will place a stain called fluorescein in your dog’s eye and uses a special light to look for evidence of corneal ulcers.

• Intraocular pressure: Your veterinarian will numb the surface of your dog’s eye (i.e., the cornea) with a drop of topical anesthetic, such as proparacaine. He or she will then use a handheld device called a tonometer to measure the pressure inside the eye. High pressure can indicate glaucoma, whereas low pressure may indicate uveitis.

For severe eye issues, your veterinarian may refer you to a veterinary ophthalmologist.

Treatment of Cloudy Eyes in Dogs

Treatment of cloudy eyes in dogs depends on the underlying cause:

• Nuclear sclerosis: Treatment is not needed since this is a normal condition that does not interfere with vision.

• Cataracts: Surgery (i.e., phacoemulsification) is preferred for cataracts, especially before they reach an advanced stage. Medical management may be necessary if secondary issues like glaucoma or uveitis develop.

• Ulcers: Most ulcers are managed medically with topical pain medications, such as flurbiprofen, medications that enhance healing like BioHAnce Ocular Repair Gel or topical serum drops, and topical antibiotics like neomycin/polymyxin B/bacitracin. Severe ulcers may require surgery performed by a specialist.

• Corneal scarring: Treatment is typically not necessary.

• Corneal dystrophy: Treatment is typically not necessary; however, if your dog develops ulcers or pain, you may be referred to a veterinary ophthalmologist for management.

• Corneal endothelial degeneration: Initially, treatment may involve a topical solution, such as hypertonic saline, to pull fluid from the cornea. In some cases, a veterinary ophthalmologist may perform a specialized surgery to prevent the condition from worsening.

• Dry eye: Most cases of dry eye can be treated with topical lubricants and a topical immunosuppressant called cyclosporine.

• Glaucoma: Medications may be given in the hospital to reduce pressure quickly. At home, glaucoma is usually treated with topical medications that prevent pressure from rising, such as dorzolamide and timolol and latanoprost. If the eye is blind and painful, removal is recommended to reduce pain.

• Anterior uveitis: Your pet is likely to be placed on topical steroids, such as prednisolone, or topical anti-inflammatory medications like flurbiprofen, to reduce inflammation in the eye. Your dog may also be given topical atropine to help with pain and reduce changes to the inner eye.

  • If an infection is suspected, topical antibiotics, such as neomycin/polymyxin B/bacitracin or ofloxacin, may be recommended. If antibiotics and steroids are both needed, neomycin/polymyxin B/dexamethasone drops may be an option.

For eye conditions that cause pain or require topical treatment, your veterinarian is likely to recommend a recovery cone to prevent further damage to the eyes.

The cone must be rigid to prevent your dog from scratching their eyes or rubbing their eyes on objects such as furniture.

Soft cones and donut cones are usually not sufficient.

Prevention of Cloudy Eyes in Dogs

There’s nothing you can do to prevent the normal cloudiness that comes with age in the form of nuclear sclerosis.

While you can’t completely prevent many causes of cloudy eyes in dogs, consider the following tips:

• Schedule regular wellness exams as recommended by your veterinarian. Your veterinarian should look at your dog’s eyes as a component of this exam. This will allow for earlier intervention if changes are noted.

• If you notice any changes to your dog’s eyes or are concerned that they’re losing vision, have your dog examined.

• Prevent injury to your dog’s eyes. For example, don’t let them hang their head out the window of a moving vehicle.

Dogs with inherited conditions that cause cloudy eyes, such as inherited cataracts, should not be bred to prevent them from passing on the condition.