Eye Issues That Cause Blindness in Dogs & Cats

One of the most powerful and important senses we have is sight. To process visual information requires devotion of more than 50% of the surface of the brain. Additionally, all other senses are influenced by vision, which, in turn, influences how we see the world.

A 2022 survey of Americans revealed that 77% of people viewed sight as the most important sense. This, in part, explains why we become distressed when our pet’s vision is diminished or lost. We fear for their quality of life and how it may impact our bond with them.

It is often shocking to pet owners how well, with time, pets adjust to vision loss. Sudden loss of vision versus a gradual loss can be more difficult and off-setting, but, regardless of how fast or slow your dog or cat became blind, with time, proper care, environmental improvements, and training, your pet can adapt, engage in activities, and have a good quality of life. So, don’t lose hope if your pet’s vision is diminishing or lost.

Symptoms of Vision Impairment in Pets

Knowing what signs your pet may exhibit when their vision is impaired or lost can help you know when to take them to a veterinarian, which is important.

Signs of vision loss you may notice include:

• Behavior changes such as anxiety, fear, or aggression

• Eye changes
  • Red
  • Cloudy
  • Puffy
  • Swollen
  • Inflamed
  • Dilated pupils
  • Iris color change
    
    

• Pawing at eyes or face

• Avoidance of new places

• Bumping into objects

• Acting confused or dazed

• Reluctance to go out in the dark

• Reluctance to walk in dim lighting

Medical Issues That Cause Blindness in Pets

Let’s explore what conditions can lead to blindness and how they can be potentially treated or managed so that you will be well-prepared for what is to come.

Cancer

Cancer within or near the eye as well as brain tumors or nerve tumors can cause blindness.

Eye tumors

Primary uveal melanoma is the most common eye tumor in both cats and dogs.

In dogs, they are often benign (non-cancerous). In cats, iris melanoma, which is rare, is malignant (cancerous). But limbal melanomas in cats, are less common and are benign.

In cats, the average age for eye tumors is 10 years old. In dogs, the average age for eye tumors is 9 years of age with a range from 7 to 10 years. But dogs as young as 2 to 4 years of age have also been diagnosed with eye tumors.

Symptoms can include swelling around the eye, excessive tearing, rubbing of the eye or face, iris color change, changes to the size of the pupil, changes in eye shape or size, and excessive blinking or squinting.

Brain tumors

Brain tumors can cause vision loss. In cats, the average when they get brain tumors is 10 to 12 years of age. For dogs, the average age is 9 to 11 years old.

Breeds with the highest incidence of brain tumors, though it isn’t known why, include domestic shorthair cats, Golden Retrievers, Labrador Retrievers, Boxers, Boston Terriers, and mixed breeds.

Clinical signs of a brain tumor can include changes in behavior, including aggression, sudden blindness, head tilt, seizures, changes in appetite, circling, abnormal gait, tremors, lethargy, and abnormal eye movement (nystagmus).

Tumor Treatment

Treatment will vary based on the type and location of the tumor. 

For eye tumors, treatment can include surgery, laser therapy, radiation therapy, chemotherapy, enucleation (surgical removal of the eye) as well as other medical therapies.

Treatment for brain tumors can include surgery, radiation therapy, chemotherapy, and palliative care.

Cataracts

Cataracts occur when there is cloudiness of the lens of the eye(s) resulting from a significant change in the structure and integrity of the proteins and/or the other components that make up the lens. These changes result in an “opacification” of the lens, which prevents light from getting through to the retina where vision is “triggered.”

Both young and old dogs can be affected by cataracts. There are several causes of cataracts in dogs, which can include genetic inheritance, metabolic disturbances such as diabetes, nutritional imbalances, trauma, and chronic uveitis (an inflammatory disease of the middle layer of the eye). A genetic predisposition has been noted in American Cocker Spaniels, Bichon Frise, Boston Terriers, Golden Retrievers, and Siberian Huskies.

Compared to humans and dogs, cataracts are less common in cats. They are most common in older cats, with the average age being about 9.5 years. Causes of cataracts in cats include age, genetics, trauma, metabolic disorders, inflammation (from trauma, infection autoimmune disease), radiation, electric shock, exposure to toxic substances, lens dislocation, and uveitis. A genetic predisposition has been noted in Himalayans, Birmans, British Shorthairs, and Persians.

The progression of cataracts cannot be slowed by medications. There is some evidence that cataracts caused by diabetes may be prevented or the formation slowed with topical aldose reductase inhibitors (ARIs).

Cataract Treatment

Treatment involves surgical removal of the cataracts. About 92.6% of cats and 90% of dogs regained vision following surgery.

Cloudy eyes don't always lead to blindness. It can just be a natural part of aging. Read more about lentincular (nuclear) sclerosis.

To learn more about cataract treatment, check out this video of cataract surgery in a dog. (Don’t worry, there isn’t any blood shown in this video. Of course, it is surgery on an eye, so if the thought of that alone makes you queasy it might be best to skip it.)

Conjunctivitis

Conjunctivitis is the term used when there is irritation or inflammation of the conjunctiva tissue that lines the inside of the eyelids and covers the white part of the eyeball (sclera). It is common in both cats and dogs.

Symptoms of conjunctivitis may include squinting, redness of the eye, swelling of the eye region, rubbing the eye, nasal discharge, sneezing, and coughing.

While blindness is a rare consequence of this condition, it can happen if not treated.

Conjunctivitis Treatment

Treatment includes topical eye therapy and oral medications. Treatment also involves identifying underlying causes, which can include infections (bacterial or viral), allergies, injury, or dry eye, and properly treating and managing them. 

Corneal Disorders

Disorders of the cornea is a general term to describe different conditions, such as inflammation within or outside the cornea, ulcers, corneal dystrophy (the structure and function of the cornea deteriorates), and trauma, that affect the cornea.

The cornea, which is the transparent portion on the front surface of the eye that covers the pupil and iris, is essential for proper vision. Any trauma or damage to it can potentially lead to blindness if not treated or managed.

Symptoms may include eye pain, watery eyes, red eyes, tearing, rubbing eye, bluish appearance to the eye, excessive blinking, or irregular surface of the eye.

Treatment for Corneal Disorders

Treatment will be dependent on which condition is present and its severity. For example, superficial corneal ulcers may be treated with topical eye medications and pain meds, whereas deep or complicated cases may need both medical and surgical management.
 

Diabetes

Diabetes can cause blindness.

In dogs, cataracts are a common complication of diabetes, with 75% of dogs developing them. As mentioned above, cataracts can lead to blindness. Diabetic cats don’t typically develop cataracts.

In addition to potentially causing cataracts (in dogs), diabetes, if not treated promptly or managed appropriately, can cause poor tear quality and production which can lead to dry eye, a potential cause of blindness in both dogs and cats.

Since diabetes is associated with hypertension, this can cause issues with the retina, such as edema and hemorrhage, which can eventually lead to retinal detachment and blindness.

High blood fat levels, associated with diabetes can lead to increased levels of fat in the front chamber of the eye and retina, both of which affect vision.

Clinical signs of diabetes include weight loss, increased thirst and urination, changes in appetite, and recurring infections.

Diabetes Treatment

Diabetes requires lifelong management with insulin and routine monitoring. To learn more about diabetes, read these related articles for dogs and cats.

Entropion

Dog breeds predisposed to entropion include Bull Mastiffs, Bloodhounds, Great Danes, Saint Bernards, Labrador Retrievers, Golden Retrievers, Norwegian Elkhounds, Rottweilers, Irish Setters, Toy and Miniature Poodles, Chow Chows, Pugs, Shar Peis, American Cocker Spaniels, and English Bulldogs.

Cat breeds that are predisposed include brachycephalic breeds such as Burmese, British Shorthairs, Himalayans, and Persians.

Clinical signs may include squinting, excessive tearing, cloudy eyes, rubbing of eyes, swelling of the eye region, eye discharge, and pain.

Entropion Treatment

Treatment depends on age and severity. For puppies, kittens, and young pets, your veterinarian may recommend lid tacking, which is a temporary procedure that pulls the lid into a more natural position while your pet grows.

Generally, surgery is required to correct the issue.

Glaucoma

Glaucoma is a painful disease that occurs when fluid builds up in the eye, resulting in increased intraocular pressure. Glaucoma can be primary, meaning it is inherited, or secondary, meaning it occurs because of another medical issue (i.e., cataracts, lens luxation, inflammation, cancer, etc.) or trauma.

Glaucoma can occur at any age in dogs but on average occurs around 8 years of age. Dogs predisposed to primary or inherited glaucoma include Basset Hounds, Beagles, Cocker Spaniels, Chow Chows, Poodles, and many terrier breeds. Mixed-breed dogs can be affected as well.

Primary glaucoma is relatively rare in cats. But the breeds predisposed include Burmese and Siamese. Middle-aged to older (about 7 years plus) cats are most commonly affected.

Clinical signs of glaucoma may include eye pain, dilated pupils, redness, squinting, watery ocular discharge, change in appetite, and avoidance of light.

Glaucoma Treatment

Rapid treatment is essential as this is a painful condition and provides the best opportunity to preserve vision. Treatment often involves eye medications, but additional systemic medications (affecting other body systems, not just the eye) may also be needed. Medical treatment is lifelong to keep pets comfortable. Surgery may be necessary if pets don’t respond to other treatments.

Since this is a progressive and incurable disease, even with treatment, blindness often occurs.

Hypertension

It is a common cause of ocular changes in dogs and cats.

Symptoms of hypertension include nosebleeds, disorientation, blood in urine, heart murmur, depression, disorientation, uncoordinated movements, and sudden blindness.

Hypertension Treatment

Treatment is dependent on the underlying cause if one is identified. In addition to treating and managing the cause, medications are used to manage the hypertension.

If blindness occurs, it cannot be reversed with treatment.

Note: In dogs with chronic kidney disease, hypertension occurs in about two-thirds of cases. Hypertension has also been observed in up to 50% of cases of dogs with diabetes.

Signs of chronic kidney disease are present in 60% of cats diagnosed with hypertension. Of the cats diagnosed with hyperthyroidism, 20 % have hypertension. Therefore, any cats with these conditions should be screened routinely for hypertension.

Keratoconjunctivitis Sicca (KCS)

Keratoconjunctivitis sicca (KCS), which is commonly called dry eye, is a condition that results from an inadequate production of tears which results in inflammation of the cornea and drying of the surrounding tissues.

The condition is usually noted in dogs between 4 and 6 years of age, but any age can be affected. Dog breeds predisposed to KCS include American Cocker Spaniels, Bloodhounds, Boston Terriers, Cavalier King Charles Spaniels, English Bulldogs, English Bull Terriers, English Springer Spaniels, French Bulldogs, Lhasa Apsos, Miniature Schnauzers, Pekingese, Pugs, Samoyeds, Shih Tzus, West Highland White Terriers, and Yorkshire Terriers.

Cats of any age and breed are susceptible to dry eye.

Common conditions that cause dry eye include immune-mediated inflammation of the glands that produce tears, congenital traits, genetics, hypothyroidism, infections from viruses, such as canine distemper or feline herpes virus, medications such as sulfa drugs, and nerves going to the tear glands can be damaged by inner ear infections, surgical removal rather than repair of a cherry eye, trauma, or other causes.

Symptoms may include redness, excessive blinking, cloudy eyes, ocular discharge, crusty eyes, and squinting.

Keratoconjunctivitis Sicca Treatment

KCS treatment involves lifelong topical eye medications.

In some cases, surgery may be recommended, especially for dogs with protruding eyes and those that are hard to medicate.

Progressive Retinal Atrophy

It occurs commonly in dogs but rarely in cats.

Pure-breed dogs are most commonly diagnosed with this condition, but mixed-breed dogs can have it as well. Breeds that are most predisposed to the degenerative form include American and English Cocker Spaniels, Akitas, Longhaired and Wirehaired Dachshundss, Labrador Retriever, Miniature Poodles, Papillons, Samoyeds, and Tibetan Terriers. Those predisposed to the less common type, photoreceptor dysplasia, include Cardigan Welsh Corgis, Collies, Irish Setters, Miniature Schnauzers, and Norwegian Elkhounds.

Clinical signs may include dilated pupils, hesitance to go into brightly lit rooms or down stairs, and bumping into things.

This condition has no treatment or cure. It's not painful but will eventually cause total blindness.

Retinal Detachment

Retinal detachment occurs when the retina becomes separated from its underlying tissue. The retina is a thin layer of tissue at the back of the eye that contains the cells that sense light and change it into electrical signals that are processed in the brain.

The common causes of retinal detachment are high blood pressure (hypertension), trauma, inflammation, infectious diseases (e.g., FIP, FeLV, Blastomyces, Brudelosis), systemic diseases (e.g., kidney disease), genetics, glaucoma, infections, intra-ocular tumors, or immune system dysfunction. High blood pressure or trauma are generally the most common causes of this condition. In some cases, there is no apparent cause.

Dog breeds prone to this condition include American Cocker Spaniels, Bedlington Terriers, Border Collies, English Springer Spaniels, Labrador Retrievers, Miniature Schnauzers, Samoyeds, and Shih Tzus.

Clinical signs may include sudden blindness, dilated pupils, blood in the eye, and differences of vision in different lighting situations.

Retinal Detachment Treatment

For there to be a chance for a return of vision, rapid treatment is critical. Determining the underlying cause is an essential aspect of treatment. Surgery may be needed to prevent it from getting worse or to repair a tear in the retina. In cases where the detachment is caused by a tumor, removal of the eye may be necessary.

Sudden Acquired Retinal Degeneration (SARDS)

Sudden acquired retinal degeneration is a poorly understood condition that causes rapid retinal degeneration, resulting in permanent blindness.

The cause is unknown, but many pets also have endocrine issues such as Cushing’s or hypothyroidism.

The average age for dogs to have SARDS is 8.5 to 10 years old. Spayed females are more likely than males to be affected. Breeds most commonly getting this condition include Beagles, Bichons, Brittany Spaniels, Cocker Spaniels, Dachshunds, Maltese, Miniature Schnauzers, Pugs, Springer Spaniels, and Shih Tzus.

This condition can occur in cats but is rare. It is caused by a taurine deficiency, but since taurine is added to cat food diets and even many dog foods contain it, deficiencies do not tend to occur.

There are no known ways to prevent or treat this condition.

Toxins

Toxins can cause blindness in pets. They can include medication, if overdosed, such as ivermectin or enrofloxacin, as well as some that have an unknown cause of blindness such as baclofen (skeletal muscle relaxant).

Household products such as organophosphates (e.g., herbicides, insecticides, or pesticides), ethylene glycol (antifreeze), or lead (e.g., fishing tackle, drapery weights, toys manufactured prior to the late 1970s).

Identifying the potential toxin is important for treatment.

Trauma

Trauma to the eye, eye area, or the head can cause blindness. Such traumas can include corneal abrasions from a fight or foreign object, blunt force trauma to the eye area or head due to a fall or being hit by a car, causing bleeding in the eye’s interior, retinal detachment, or causing the eyeball to be dislodged.

Treatment will be dependent on the type of trauma.

Uveitis

Uveitis is the term used to describe inflammation inside the eye that usually occurs due to leaky blood vessels in the iris. This serious and painful condition can lead to blindness and prompt aggressive treatment is essential.

Identifying potential underlying causes is critical, so a detailed diagnostic workup is required. Some causes of uveitis include immune-mediated diseases, high blood pressure, cancer, viruses (FeLV, FIV, FIP, canine distemper virus), parasites (e.g., toxoplasmosis, ehrlichiosis), fungal (e.g., blastomycosis, histoplasmosis, coccidiomycosis), or trauma.

Clinical signs of uveitis include squinting or keeping their eye shut, elevated third eyelid, rubbing the eye or face, excessive tearing, very red eye, avoiding bright light, and decreased vision.

Uveitis Treatment

Treatment must be prompt and aggressive to prevent adverse side effects from the condition. Treatment can include topical eye therapy as well as systemic (whole-body) therapy. Underlying causes must be treated and managed as well. If they are not, the uveitis may re-occur or persist.

Viruses

Identifying the cause of the infection is essential for the appropriate treatment to be initiated. Treatment can include topical eye therapy as well as systemic antibiotics or antifungals.

How to Help Your Dog or Cat Adapt to Vision Loss

We are here to help you navigate how you can train and support your pet through this process to maintain your special bond with them.

Adapting to vision loss and eventual blindness can be challenging for pets and their guardians, but with proper care, dogs and cats can continue to live happy, fulfilling lives.

Key Steps to Help Your Pet If They Have Vision Loss

1. Maintain a consistent environment

Keep the home layout consistent to help pets navigate using memory and other senses. Don’t move furniture around. Use rugs or mats of different textures to help your pet know which room they are in. For example, a soft water-absorbing microfiber rug on the inside of the door that leads to a yard, and a sturdier, rubber mat outside of the door. You can also use carpet runners throughout your home to create pathways for your pet to follow and give them a sense of safety as they move about.

2. Use scent and sound cues

Enhance the environment with scented markers and noise-making items to help pets locate important objects like food bowls, toys, cat trees, and their beds.

Here are some toys that make sounds:

Gigwi Interactive Cat Toy with Real Chirping Bird Electronic Sound Squeaky and Feather

Potaroma Chirping Cat Toy Balls – Great for putting catnip or silvervine inside

Wobble Wag Giggle Ball – Interactive Dog Toy with Giggle Sounds 

Pet Qwerks Talking Babble Ball - Interactive Dog Toy 

3. Train with verbal cues

Teach simple verbal cues like “step up” and “step down” to guide your pet around obstacles. Dogs are incredibly attuned to body language and hand signals, and may not know specific verbal cues that you would assume they do. Be patient and consistent and they’ll learn quickly.

4. Create a safe zone

Designate a hazard-free area with their bed, water bowl, and favorite toys to provide a sense of security. For your dog, plug in a calming pheromone diffuser and turn on some white noise or calming music, if needed, to promote rest.

5. Schedule regular vet visits

Regular check-ups are essential to monitor vision loss and manage underlying conditions. This way you can better understand where they are in the progression of their vision loss and adjust routines or their environment accordingly.

6. Use and provide interactive toys and activities

Mental enrichment is key to keeping your pet’s brain sharp and decreasing anxiety. Enrichment activities and interactive toys or puzzle feeders activate the other senses and provide an outlet for instinctual needs.

Learn more about ways to enrich your pet in our following articles:

Dog Enrichment: Toys, Games, and DIY Ideas

Choosing Interactive Dog Toys and Feeders

Cat Interactive Food Toys and Puzzles

Cat Enrichment: What to Do if Your Cat Is Bored

7. Provide emotional support

Offer plenty of affection and patience as your pet adjusts to their new way of navigating the world. While it’s a big change, don’t forget that your pet has amazing other senses they rely on. Dogs and cats are quite resilient!

Remember, life is a journey, and this is but a bump in the road. You and your pet will get through this. Embrace the experience, have a positive attitude, grow in knowledge, and cherish every moment you share together.