Dog Cataracts  

We love our furry companions, but just like us, they age over time. If you notice that not only the fur but also your pet’s eyes are becoming increasingly grey, your dog might be suffering from cataracts. This article covers all the important facts about cataracts in dogs. . 

What Are Cataracts in Dogs? 

Cataracts, also known as lens opacifications, refer to the clouding of the eye’s lens due to pathological changes. The name comes from the eye’s grey appearance, with the lens eventually turning snow-white. The eye’s lens sits between the rear chamber and the vitreous body and consists of an anterior and posterior capsule, a cortical layer, and a lens nucleus.

For vision, a transparent lens is necessary, which is achieved by the dense fibre arrangement in the cortex and nucleus. The extent of vision impairment depends on the changes in the fibre structure and the severity of the lens opacity. 

Understand that it’s also crucial to differentiate between a mild, age-related lens opacity (nuclear sclerosis), which rarely leads to a dog’s blindness. 

Symptoms: What Are the Key Signs? 

Cataracts in dogs are characterised by the grey clouding of one or both eye lenses and the loss of vision. Since cataracts progress over months or years, they are classified into different stages.

Early Stage of Cataracts in Dogs 

In the early stage, cataracts in dogs appear as small, faint spots of lens clouding, which grow over time. If the condition worsens and the back of the eye is no longer visible, it’s considered mature cataracts. At this stage, the dog is mostly blind. As the disease progresses, the lens may disintegrate, leading to severe and very painful eye inflammation. This hypermature cataract sometimes comes with a yellowish tint to the lens. 

Advanced Stage 

In advanced stages, the lens may shift (lens luxation), potentially causing glaucoma. This condition is very painful and should be treated by a vet as soon as possible. 

How Does a Dog with Cataracts See?

As cataracts develop, the dog’s vision gradually dims, with less light passing through the clouded lens. The dog sees everything through an increasingly dense fog. In the early stages, this can be hard for owners to detect. The dog may struggle to navigate in the dark or in poor lighting. Because of the reduced or lost vision, dogs often show increased disorientation, reluctance to move, and bumping into objects and people. If only one eye is affected, some dogs might compensate using the healthy eye. 

Diagnosis: How Do I Identify Cataracts in Dogs? 

If you suspect your dog has cataracts, promptly visit the vet for an examination. The vet will inquire about behavioural changes and other indicators during the anamnesis. A general examination follows to exclude underlying conditions such as diabetes mellitus. Then, specific eye tests are conducted to identify potential vision problems. 

The vet will closely examine the dog’s general movements and the outer eye. Subsequent tests will help diagnose any vision issues. For a detailed view of the inner eye structures, special eye drops are used to dilate the pupil. 

The following medical tools assist in the diagnosis: 

• Using a slit lamp, the vet precisely locates the lens opacities 
• With a specialised ultrasound device, the vet assesses the health of the lens and other eye structures 
• The electroretinogram (ERG) provides additional insights into any existing retinal damage 

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Treatment: How Are Cataracts in Dogs Treated? 

Unfortunately, there are no currently approved medications to halt the progression or cure cataracts in dogs. The best treatment presently is the surgical removal of the lens, performed under general anaesthesia. This surgery is only viable if the dog’s retina is intact. Don’t delay the operation; the more advanced the cataracts, the more significant the changes in the eye, reducing the success rate of the surgery and increasing post-operative complications. 

Post-surgery, intensive aftercare is essential. For the first few weeks, you will need to administer various eye drops to your dog several times daily. Regular follow-up check-ups with your vet are also important. 

Causes: What Leads to Cataracts in Dogs? 

Vets distinguish between congenital and acquired cataracts in dogs. 

Congenital Cataracts in Dogs 

Hereditary cataracts (HC) are recessively inherited and usually affect both eyes. Breeds like Labrador Retriever, Golden Retriever, Husky, Schnauzer and Afghan Hound are particularly susceptible. Another congenital eye disorder is progressive retinal atrophy (PRA), which can occur in all dog breeds and leads to retinal degeneration. This complex condition can also result in cataracts. 

Acquired Cataracts 

Acquired cataracts are the most common and occur either due to aging (primary cataracts) or due to eye diseases (secondary cataracts). Conditions like eye inflammation (uveitis), injuries, malformations of eye structures like the retina, and systemic diseases like diabetes mellitus (diabetes) fall under this category. Up to 60% of dogs with diabetes mellitus develop cataracts, typically in both eyes. Rarely, toxins and physical stimuli such as radiation can cause the condition. 

Prognosis: What Are the Chances of Recovery? 

The prognosis for cataracts in dogs depends on the disease stage. If all examinations indicate that surgery is viable, there’s a 90 to 95% chance of restoring vision. However, if internal eye structures have inflamed or the lens has detached, the likelihood decreases. 

Prophylaxis: Can Cataracts in Dogs Be Prevented? 

Due to age-related and genetic causes, there are few prophylactic measures. However, you can reduce the risk of developing diabetes mellitus through a healthy diet and sufficient exercise.