Cataracts in dogs are eye diseases that affect the lens of the eye. This lens becomes opaque and whitish, greenish or bluish, hindering the dog's vision.
This prevents light from passing properly to the retina, resulting in blurred vision and, if left untreated, can develop into total blindness.
Cataracts can occur in one or both of a dog's eyes and can develop quickly, within a few weeks, or more slowly, over months or even years.
It's important to note that not every color change in the eye means that it's a cataract. In elderly dogs, for example, nuclear or lenticular sclerosis can occur, which gives the eyes a bluish tint, but does not significantly compromise vision and does not require treatment. However, they should be monitored, as it can develop into a cataract.
On the other hand, true cataracts seriously affect visual function and tend to get worse over time.
Degrees of cataract maturity in dogs
Cataracts are a progressive disease that can present in different degrees of maturity, depending on the amount of opacity in the lens.
1. Incipient cataract (or phaco-sclerosis)
- What it is: It is the initial stage of cataracts.
- Characteristics: Only a small part of the lens is opaque (less than 15% of the lens, usually). It can be confused with nuclear sclerosis, a normal age-related alteration that does not impair vision.
- Visual signs: There may be slight blurring in the eye, but the dog sees normally or with little loss of vision.
- Management: There is usually no surgical urgency. The cataract can be monitored with regular examinations.
2. Mature cataract
- What it is: When the lens is completely opaque.
- Characteristics: The lens has lost all its transparency, completely preventing light from passing through to the retina.
- Visual signs: The dog is practically blind in the affected eye. They often bump into objects and have difficulty finding their way around.
- Conduct: This is the ideal stage to perform phacoemulsification surgery, as long as the rest of the eye is healthy.
3. Hypermature cataract
- What it is: Advanced stage of mature cataract, with degeneration of the lens.
- Characteristics: The contents of the lens begin to liquefy and the anterior capsule (the membrane surrounding the lens) becomes contracted and has visible folds. There may be secondary intraocular inflammation (uveitis).
- Visual signs: No vision. In some cases, the eye may experience pain, inflammation and the risk of secondary glaucoma.
- Conduct: Surgery is still possible, but it becomes more complex and with a higher risk of complications. Not all dogs with hypermature cataracts are good candidates for surgery.
Symptoms of cataracts in dogs
Eyes that have a bluish or whitish tint are a classic indicator of a mature cataract in dogs, showing opacification of the lens and a consequent reduction in vision.
The symptoms that guardians can identify include visual and behavioral changes such as:
- Dull, bluish or white eyes
The lens, the center of the eye, can acquire a grayish, bluish or white color, visible to the naked eye. In some cases, the eye may show a kind of "haze" or white spots behind the pupil.
- Sensitivity to light (photophobia)
Dogs with cataracts may feel uncomfortable in excessively bright environments, so avoid places with bright light.
- Tearing and discharge
It is common to notice an increase in eye secretions and tearing, often accompanied by redness, as a result of irritation caused by the cataract or secondary inflammation.
4. Vision impairment and disorientation
As the cataract progresses, the animal has problems perceiving obstacles, bumping into furniture, walls and steps. This difficulty can also manifest itself in an inability to locate toys or recognize people from a distance.
5. Changes in behavior
Loss of vision can lead to insecurity. The pet may avoid climbing onto sofas or down stairs, be more anxious, become quieter or even show aggression due to disorientation.
In some cases, the situation can lead to depression, decreased appetite and a preference for remaining still, especially when vision is significantly compromised.
As the cataract progresses, these symptoms can worsen.
Main causes of cataracts in dogs
Canine cataracts can arise for various reasons, ranging from genetic factors to wider health problems.
Genetics and Age
The most common cause is hereditary. Many cataracts are congenital, which means that the dog is born predisposed to developing them, especially in specific breeds.
In addition, older dogs often have what is known as "senile cataracts". Generally, in these cases, the opacification is small, evolves slowly and may not lead to complete blindness.
Race predisposition
Some breeds are more prone to developing cataracts.
These include:
- Poodle
- Cocker Spaniel (both American and English)
- Miniature Schnauzer
- Yorkshire Terrier
- Golden Retriever
- Labrador
- Siberian Husky
- West highland white terrier.
In these dogs, the disease can appear at a young age, with cases of juvenile cataracts occurring before the age of 6.
Diabetes
Diabetes is the second most common cause of cataracts in dogs. Metabolic changes associated with the disease can cause cataracts to develop rapidly and bilaterally.
Around 75% of diabetic dogs develop cataracts in the first year after diagnosis, with the lens becoming whitish within a few weeks if glucose levels are out of control.
Inflammatory Eye Diseases
Inflammations inside the eye, such as uveitis, and problems with the retina - for example, Progressive Retinal Atrophy (PRA) - can trigger cataracts.
Diseases such as glaucoma can also lead to opacification of the lens. Infections (such as those transmitted by ticks) or minor trauma can initiate this inflammatory reaction which, over time, results in cataracts.
Trauma and Injuries
Any blow or injury to the eye can damage the lens, causing severe inflammation and, consequently, cataracts.
In extreme cases, when the lens capsule is ruptured, opacification is virtually certain. Certain drugs or toxins, although rare, can also be involved in this process.
Nutritional and Other Causes
Cataracts caused by nutrition, although less common nowadays, can still occur in puppies who do not receive proper nutrition due to a lack of essential nutrients.
Prolonged exposure to radiation, such as radiotherapy treatments in the eye, and congenital malformations of the eye can also contribute to the development of cataracts.
Cataracts can also develop as a result of congenital eye defects and long exposure to radiation, such as radiotherapy in the eye area.
How is canine cataract diagnosed?
A thorough eye examination is the first step in diagnosing cataracts in dogs.
Instruments such as the slit lamp and fundoscope are used. In this way, the vet assesses the health of the eye structures - from the cornea to the lens - identifying the characteristic opacity of cataracts and differentiating it from other alterations, such as nuclear sclerosis, which is common in older dogs.
In addition to the direct assessment, the specialist performs tonometry to measure intraocular pressure, which is essential for detecting possible complications such as glaucoma.
When the opacity of the lens prevents proper visualization of the back of the eye, ocular ultrasound becomes an indispensable tool for checking the integrity of the retina.
In some cases, electroretinography (ERG) is used to assess the functionality of the retina by measuring electrical activity in the face of light stimuli.
If surgery is necessary, general preoperative tests - such as blood tests and an electrocardiogram - are carried out to ensure the dog's systemic health and safety during anesthesia.
Together with the animal's clinical history, these tests determine the best treatment plan, ensuring that the diagnosis is accurate and the therapeutic approach the most appropriate for each case.
But remember to always consult a trusted veterinary professional who will lead you through the best way to diagnose your puppy.
Cataract treatment in dogs
There is currently no medicine or eye drops capable of eliminating cataracts in dogs.
Although drug treatment can help control inflammation and complications - such as uveitis or the risk of glaucoma - it is only palliative in nature, i.e. it does not reverse the opacification of the lens.
In dogs with diabetes, for example, strict blood sugar control is essential to slow down the progression of cataracts, but it doesn't make them disappear either.
Cataract surgery is the only effective method of restoring vision, and is indicated mainly when the opacity is already compromising the animal's quality of life.
The procedure consists of removing the opaque lens and, where possible, implanting an artificial intraocular lens, allowing the dog to see normally again. This surgical approach is especially recommended in cases where the cataract is progressing rapidly.
In situations where surgery is not feasible - for example, in very old dogs or those with health conditions that contraindicate anesthesia - the focus shifts to palliativecare.
For example, adaptations to the home environment, with fixed furniture and sensory references such as carpets or smells.
Frequently Asked Questions
When is cataract surgery indicated?
Cataract surgery in dogs is recommended when vision loss becomes significant and starts to affect the animal's quality of life, or when there is a risk of complications such as inflammation and increased eye pressure.
In general, the procedure is indicated for cases in which the cataract has already reached an advanced stage - such as mature or hypermature cataracts.
The decision to operate depends on the dog's age, general health and the results of eye examinations; not all patients are candidates, especially if the retina is already compromised or if there are conditions that contraindicate anesthesia.
The procedure has a high success rate, with between 85% and 90% of operated dogs having normal intraocular pressure vision at least one year after surgery, even if it's not 100% of what they had before.
Vision may not fully return and there may be a slight blurring or reduction in contrast, especially in advanced cases. But the idea is to allow them to play, run and move around safely again.
The effectiveness of the result also depends on post-operative care and the stage of the cataract at the time of surgery.
Despite risks such as infection, hemorrhage and retinal detachment, these are rare and can be reduced with proper examinations, technique and follow-up.
Therefore, talk to a veterinary ophthalmologist to assess the benefits and risks in your dog's specific case, ensuring that the intervention is carried out at the right time and in the safest way possible.
Can cataracts in dogs be cured?
Yes, cataracts in dogs can be cured, but the only way to treat them is through surgery. This procedure removes the opaque lens, restoring the passage of light and generally allowing the pet to regain its sight.
However, it's important to understand that the success of the surgery depends on the overall health of the eye. For the dog to see well again, other eye structures - especially the retina and optic nerve - need to be healthy.
When cataracts are diagnosed early and the animal is suitable for surgery, the chances are better.
Without surgery, cataracts do not heal spontaneously and tend to get worse over time.
Is it possible to reverse cataracts in dogs?
No, once a cataract has formed, it cannot be reversed or "dissolved" by conventional treatments such as eye drops or medication.
Although in the early stages the cataract can remain stable for a while, opacification of the lens - caused by irreversible changes in the proteins - can only be removed by surgery.
It's important to remember that measures such as controlling diabetes can slow down the progression, but won't eliminate the opacity that has already set in.
What medicine is there for cataracts in dogs?
There is currently no medicine that can "cure" cataracts in dogs.
Products sold as antioxidant eye drops or other supplements have no scientific evidence and, in practice, only help to control associated complications such as inflammation, uveitis or glaucoma.
The eye drops prescribed by veterinarians serve to keep the eye in better condition or to treat complications, but they cannot reverse the process of opacification of the lens.
The cost of cataract surgery for dogs in Brazil
Cataract surgery, which is the only effective treatment for restoring sight, has varying costs in Brazil.
On average, the price per eye is between R$2,500 and up to R$20,000, which can increase based on factors such as location, technology used, team specialization and pre- and post-operative examinations.
How to prevent cataracts in dogs?
Although we can't completely prevent cataracts in dogs, we can delay their appearance with a few measures. It's super important to keep diseases such as diabetes under strict control to avoid the rapid development of diabetic cataracts. In addition, annual eye check-ups are a great idea, especially for those dogs of more prone breeds or who are already older.
It is also important to avoid eye trauma, as any injury can predispose the animal to developing eye problems.
In addition, always keep your dog's vaccinations up to date to protect him from infections that can cause uveitis or other eye problems.
Even with these precautions, dogs with a genetic predisposition to cataracts can develop them, since heredity plays a significant role in the disease.
That's why it's so important to take your dog for regular check-ups with the vet. This way, any eye problems, such as cataracts, can be detected early on and the most appropriate treatment can be started so that they can continue to see well and happily!
