Cataracts in Dogs: Causes, Symptoms, and Treatments

Cataracts in dogs are a widespread eye condition manifesting with a cloudy lens appearance and progressive vision loss. Cataracts develop when protein accumulate within the lens, forming a cloudy film with a white, blue, or grey tint. 

Common causes of cataracts are age, genetics, diabetes mellitus, injury, nutritional deficiencies, inflammatory conditions, toxicity, and congenital factors. 

Cataract symptoms include cloudy eyes, changes in eye color, decreased vision, bumping into objects, squinting or blinking, difficulty navigating in dim light, rubbing the eyes, and changes in behavior.  

Prolonged cataracts lead to uveitis or eye inflammation and glaucoma or increased intraocular pressure. Blindness results from untreated canine cataracts. 

The vet-recommended standard for treating cataracts in dogs is emulsification, a surgical procedure. Eye drops and homeopathic cataract remedies exist, but their efficacy remains inconclusive. 

Check the dog’s eyes regularly for early signs of cataracts and practice frequent checkups with the vet. Cataracts in older dogs are commonly misdiagnosed as nuclear sclerosis, a lens condition associated with aging that typically doesn’t hinder vision. 

What are Dog Cataracts?

Dog cataract is an eye condition in which the lens becomes cloudy and blocks light from reaching the retina. Cataract in dogs develops when proteins in the eye clump together, forming a hazy film over the lens. 

The eye's structure and mechanism function similarly to a camera. The camera has a lens for focusing light on the film, while the eye has a lens for focusing light on the retina. 

The retina is a thin tissue layer on the back of the eye that converts light particles into signals the brain uses to form images. 

The formation of cloudy film over the lens prevents light from reaching the retina, causing vision loss or even blindness. 

The cloudy film covers small parts of the lens or the entire lens. Cataracts in dogs are classified as incipient, immature, mature, and hypermature based on severity. 

Incipient cataracts involve less than 15% of the lens and do not cause vision issues. Immature cataracts affect multiple lens layers or different lens areas and cause mild visual deficits. 

Mature cataracts cover the entire lens and result in significant vision loss or near blindness. Hypermature cataracts occur when the cloudy lens shrinks, triggering lens-induced uveitis or eye inflammation. 

What are the Causes of Dog Cataracts?

The causes of dog cataracts are listed below. 

• Age: Age is among the most common causes of cataracts in dogs. Cataracts primarily occur in middle-aged to senior dogs due to prolonged oxidative stress on the lens's epithelial cells. 
• Genetics: Inherited disease or genetic disposition is the main reason for cataracts. Certain dog breeds, like Miniature Schnauzers, Poodles, and some Terriers, are predisposed to cataracts. 
• Diabetes Mellitus: Diabetic dogs are highly susceptible to cataracts. Excess blood sugar in dogs with diabetes accumulates in the lens, eventually resulting in cataracts. 
• Injury: Traumatic injuries in dogs result in cataracts in some instances. An electric shock is a typical example of a cataract-causing traumatic injury. 
• Nutritional Deficiencies: Cataract formation is often related to dietary deficiencies, particularly in essential amino acids like tryptophan. Puppies fed commercially available milk-replacer formulas frequently lack these essential amino acids. 
• Inflammatory Conditions: Uveitis is an inflammatory condition that increases the risk of cataracts. It is a specific eye inflammation that affects the deep vascular tissues of the eye. 
• Toxicity: UV light exposure leads to cataracts in dogs and is a common cause of cataracts in humans. Radiation and exposure to toxic substances contribute to cataract formation in some cases. 
• Congenital Factors: Puppies are born with cataracts for reasons that remain unidentified on rare occasions. The same phenomenon is observable in human infants. 

What Type of Breed is More Prone to Dog Cataracts?

The type of breeds that are more prone to dog cataracts include Miniature Schnauzers, West Highland Terriers, Silky Terriers, Boston Terriers, Australian Shepherds, Poodles, American Staffordshire Terriers, Labrador Retrievers, Bichon Frise, Havanese, French Bulldogs, Cocker Spaniels, and Huskies. 

Hereditary cataracts in dogs stem from genetic defects that are more common in specific breeds. Cataract-associated risk genes are present in 59 dog breeds, according to a paper “Prevalence of Primary Breed-Related Cataracts in the Dog in North America,” published in Veterinary Opthalmology in 2005. 

Can Dogs Get Cataracts from Old Age?

Yes, dogs can get cataracts from old age. Advanced age is a primary risk factor for cataracts in dogs. Age-related cataracts, or ARC, result from long-term oxidative stress and damage to the lens epithelial cells. 

Small dog breeds develop ARC when they are around ten years old, and large dog breeds at six. 

Age-related cataracts in dogs are prevalent and suitable as an indicator of aging, according to a study titled “Age-Related Cataract in Dogs: A Biomarker for Life Span and its Relation to Body Size,” published in Journal List in 2011.  

The study featured 72 dog breeds of various sizes and life expectancies and concluded that the formation of cataracts “correlates directly with breed size and inversely with breed life span.”  

How does Diabetes Mellitus Contribute to Cataracts in Dogs?

Diabetes mellitus contribute to cataracts in dogs by increasing the amount of glucose or blood sugar reaching the lens. 

The canine body effectively rids itself of surplus blood sugar or glucose, but an overload saturates normal mechanisms, prompting glucose redirection into alternative pathways.

The lens capsule’s incapacity to diffuse the excess sugar causes its build-up. The accumulated sugar within the lens capsule attracts water, resulting in cataracts.

Preventing a high blood sugar level in dogs helps avoid diabetes-related cataracts. Obesity stemming from substandard nutrition and lack of exercise is a primary risk factor for canine diabetes. 

Diabetic dogs are highly susceptible to cataract development, and cataracts are not a sign of inadequately managed diabetes. 

“The majority of dogs with diabetes will develop cataracts within 5-6 months from the time of diagnosis of the disease, and approximately 80% of dogs will develop cataracts within 16 months of diagnosis,” states “A Retrospective-Cohort Study on the Development of Cataracts in Dogs with Diabetes Mellitus: 200 Cases,” published in Veterinary Ophthalmology in 1999. 

What is the Difference Between Cataracts and Nuclear Sclerosis?

The difference between cataracts and nuclear sclerosis is that cataract is a pathological eye condition resulting in vision loss, while nuclear sclerosis is a normal age-related change and generally doesn't impair vision.  

Nuclear or lenticular sclerosis is a bluish, transparent haze that forms in the lens of older dogs. Lenticular sclerosis is age-related and typically manifests when the dog is six to seven years old.

Nuclear sclerosis, unlike cataracts in dogs, does not cause blindness. Dogs with severe forms of nuclear sclerosis develop minor issues with visual acuity and depth perception. 

What are the Symptoms of Cataracts in Dogs?

The symptoms of cataracts in dogs are listed below. 

1. Cloudy Eyes

Cloudy eyes in dogs are the first signs of cataracts. Protein clumps accumulating within the lens cause cloudiness, manifesting as opacity with whitish, bluish, or grayish tones. Cataracts do not always indicate hazy eyes, as the treatment depends on the trigger. Cloudy eyes warrant concern and immediate veterinary attention. 

2. Changes in Eye Color

Changes in eye color are a hallmark symptom of cataracts in dogs. The color shift is only sometimes authentic, yet it appears real due to the lens cloudiness. The eye color change is not inherently harmful but indicates more serious underlying problems.  

3. Decreased Vision

Decreased vision occurs when the dog loses its ability to see. The effects of decreased vision in dogs include hesitant movements, exhibiting caution when navigating around, walking with the nose on the floor, barking at inanimate objects, and inability to find toys and feeding bowls. Decreased vision is a severe condition that requires immediate veterinarian consultation. 

4. Bumping into Objects

Bumping into objects is noticeable when vision loss progresses and the dog is unable to navigate its surroundings. Dogs with cataracts stumble into walls, door frames, and furniture, and owners report a sudden clumsiness in their pets’ behaviors. The best way to treat bumping is to avoid moving furniture and making structural changes to the dog’s home environment. 

5. Squinting or Blinking

Squinting involves partially opening the eyes while blinking, which refers to frequent eyelid movement. Squinting and excessive blinking indicate cataracts in dogs and develop due to light sensitivity. Dimming the lights helps alleviate symptoms of light sensitivity temporarily until the dog undergoes surgical treatment for cataracts.

6. Difficulty Navigating in Dim Light

Dogs with cataracts exhibit increased confusion and difficulty navigating dim-light environments, often bumping into objects. Dim light exacerbates vision problems, hindering the dog’s ability to navigate familiar surroundings. Impaired vision in low-light conditions is not exclusive to cataracts, and treatment options vary based on the root cause.

7. Rubbing the Eyes

Rubbing the eyes refers to the dog using their paws to scratch or rub their eyes and face against surfaces like carpets and blankets. Cataracts do not cause eye itchiness, but dogs rub their eyes to clear their vision. Persistent eye rubbing due to itchiness suggests other underlying eye conditions in dogs and requires prompt veterinary care. 

8. Changes in Behavior

Changes in behavior are common in dogs with cataracts. Sudden clumsiness, unexplained confusion, and anxiety are common behavioral symptoms of cataracts. The inability to move around unencumbered creates bewilderment and panic in the dog. CBD oil for dog behavior problems helps calm panicked dogs and supports relaxation. 

What is the Early Sign of Cataracts in Dogs?

The early sign of cataracts in dogs is a cloudy lens. The cloudiness or opaqueness covers the entire lens or a small surface of the lens and is present on one or both eyes. The hazy film over the lens presents a white, gray, or blue hue, giving the eye a textured appearance. 

Cataracts in dogs are difficult to spot initially due to a lack of obvious visual symptoms. An in-depth and regular eye examination helps detect subtle signs of lens clouding. 

What are the Treatments for Cataracts in Dogs?

The treatments for cataracts in dogs are listed below. 

• Surgery: Surgery is the golden standard for treating cataracts in dogs. The best procedure is called phacoemulsification. Phacoemulsification is a state-of-the-art approach in which the surgeon uses ultrasound to disperse the lens material into liquid and aspirate the liquid through a tiny incision. The removed lens is replaced with an intraocular lens implant (IOL) to restore regular vision in cases where the dog is a suitable candidate. Phacoemulsification has “success rates between 70 and 95%” based on a study “Clinical Assessment of Cataracts in Dogs” by D. Gould in 2002. 
• Eye Drops: Topical medications or eye drops for cataracts are a controversial topic. Aldose reductase inhibitors (ARIs) delay the onset or progression of cataracts in dogs with Diabetes Mellitus based on a study, “Topical Kinostat™ Ameliorates the Clinical Development and Progression of Cataracts in Dogs with Diabetes Mellitus,” published in Veterinary Ophthalmology in 2010. Lanosterol reduces the severity of naturally occurring cataracts, according to the paper “Lanosterol Reverses Protein Aggregation in Cataracts,” issued in Nature in 2015. The widespread efficacy of eye drops in treating cataracts is limited. Aldose reductase inhibitors are prohibitively expensive and must be used following a strict schedule, while lanosterol has a poorly understood action mode. 
• Homeopathic Products: The modern pet market offers specific homeopathic remedies formulated to treat cataracts or delay their progression. These homeopathic cataract remedies are not vet-approved or a viable substitute for surgery. 

How can I Help my Dog with Cataracts?

You can help your dog with cataracts by ensuring treatment, managing the dog’s light sensitivity before the surgery, and supporting their eye health post-surgery. 

Supplements rich in vitamin C, vitamin E, beta-carotene, fish oil, and antioxidants promote healthy eyes. Eye health supplements are readily available and formulated exclusively for dogs. 

Cataracts in dogs culminate in blindness, but blind dogs are still able to live fulfilling lives. Teach the dog to respond to vocal commands to improve communication and avoid rearranging household furniture to help it navigate its surroundings.     

How does Dog's Immunity Contribute to Cataract Development in Dogs?

The dog’s immunity contributes to cataract development by defending against eye infections. Severe and prolonged inflammation of the eye, known as uveitis, is a common risk factor for cataracts in dogs. 

A strong dog immunity resists pathogens responsible for uveitis. A robust immune response is vital for preventing infectious diseases.  

Does Home Remedy Help Dogs with Cataracts?

No, a home remedy does not help dogs with cataracts. Home remedies like administering certain vitamins and antioxidants assist with some cataract-related symptoms but are not therapeutic. Cataracts in dogs occur inside the lens and require surgery. 

Never treat dog cataracts at home. Consult the veterinarian about the dog’s candidacy for cataract surgery and use eye health supplements as a supplementary treatment if the vet approves. 

Is there a Way to Prevent Dogs from Having Cataracts?

No, there is no way to prevent dogs from having cataracts. Pet owners who are able to identify issues early on reduce the risk of permanent blindness occurring due to cataracts in dogs. 

The main prevention tip is to inspect the dog’s eye regularly for early signs of cataracts. Routine checkups with a licensed veterinarian are essential for cataract-prone breeds. 

Always take the dog to the veterinarian for immediate care in case of eye injuries and trauma stemming from noticeable eye changes. 

Dog breeders are encouraged to avoid breeding dogs with cataracts due to the condition’s hereditary nature.  

What Happens if Dog Cataracts Are Left Untreated?

If dog cataracts are left untreated, they result in blindness. Blindness in dogs significantly reduces the dog’s quality of life and is a common complication of cataracts. 

Failing to treat cataracts in dogs “can lead to blindness and lens-induced uveitis,” states the author of “Diabetic Cataract in Dogs: Complications, Treatment, Outcomes,” published in the International Journal of Veterinary Medicine in 2022.  

Does Cataracts in Dogs Lead to Glaucoma?

Yes, cataracts in dogs lead to glaucoma. Untreated cataracts cause lens-induced uveitis, culminating in glaucoma. Uveitis is inflammation of the eye’s middle layer, the uvea or uveal tract. 

Severe uveitis and other eye problems in dogs affect the eye's internal pressure and result in eye hypertension or glaucoma. 

Postoperative glaucoma develops in dogs undergoing cataract surgery. “Routine antiglaucoma medication use in the first 12 hours after surgery” is vital,” according to a 1996 paper “Ocular Hypertension Following Cataract Surgery in Dogs: 139 Cases (1992-1993).”