🐶 Cataracts in Diabetic Dogs – A 2025 Vet's Guide to Surgery, Vision, and Care

By Dr Duncan Houston, BVSc

👁️ What Are Cataracts?

A cataract is a cloudiness or opacity in the lens of the eye that blocks light from reaching the retina. In simple terms, it prevents dogs from seeing clearly—or at all—depending on severity. Cataracts can affect the entire lens or just a portion of it. 🌀

💉 Why Do Diabetic Dogs Get Cataracts?

The lens is a transparent, living structure suspended by fine fibers inside the eye. It absorbs glucose from the fluid that bathes it. In a diabetic dog, blood sugar levels are high, and so are sugar levels in this eye fluid. 🧪

Excess glucose is converted into another sugar called sorbitol by an enzyme known as aldose reductase. Sorbitol attracts water into the lens, disrupting its clarity—this process creates the opacity known as a cataract. Fructose also contributes to this change. ⚠️

Even well-managed diabetic dogs can develop cataracts. It’s not a sign of poor diabetic control—it’s simply a common consequence of diabetes in canines. 🐾

⏳ How Fast Do Cataracts Develop?

In most diabetic dogs, cataracts develop rapidly—often within weeks of diagnosis. Sudden blindness can be shocking for pet parents. Fortunately, science is catching up. 🧬

🔬 A Glimpse of Hope: Kinostat®

Kinostat® is an aldose reductase inhibitor designed to block the enzyme responsible for producing sorbitol. By stopping sorbitol accumulation, Kinostat may help prevent or delay cataract formation in diabetic dogs. 🧴

Note: Kinostat is not yet widely available commercially and must be started early in diabetes diagnosis—it cannot reverse cataracts once they form. ⛔

🔍 What Does Cataract Maturity Mean?

Vets classify cataracts based on how much they impair vision, which is done by evaluating how much of the tapetum (a reflective layer at the back of the eye) is visible: 🌈

• ✨ Very Early: Less than 10% obscured—minimal vision impact
• ⚪ Early Immature: 10–50% obscured
• ⚪⚪ Late Immature: 51–99% obscured
• ⚫ Mature: Entire tapetum is obscured—full vision loss
• 🧊 Hypermature: Lens starts dissolving; inflammatory and painful

Hypermature cataracts can cause painful inflammation called uveitis. Diabetic cataracts often become hypermature quickly, creating complications. 🔥

😵‍💫 What Is Uveitis?

Uveitis is inflammation of the vascular part of the eye and is common in advanced cataracts. Symptoms include redness, squinting, and constricted pupils. If present before surgery, uveitis significantly lowers surgical success rates. ⚠️

👨‍⚕️ Can Cataract Surgery Restore Vision?

Often, yes—if the eye is otherwise healthy. A thorough examination by a veterinary ophthalmologist is essential. ✅

🧪 Key Tests Before Surgery:

• ERG (Electroretinogram) – Measures retinal function ⚡
• Ocular ultrasound – Assesses internal eye structure 📡
• Uveitis check – Ensures inflammation is controlled 🧯

Vision restoration is possible only if the retina and other internal eye structures are functional. Cataract surgery won't help if the damage is already irreversible. 🧠

🚫 Do Cataract-Dissolving Drops Work?

No. Despite the marketing, there is no scientifically proven eye drop that can dissolve or reverse cataracts in dogs. Relying on these could waste critical time and worsen your dog’s condition. 💸

😔 Is It Cruel to Keep a Dog Blind?

Absolutely not. Dogs adapt incredibly well to vision loss, especially when the environment is familiar. 🏡 As long as the blindness isn’t painful, your pup can still lead a joyful, fulfilling life. Just avoid rearranging furniture and always supervise them closely. 🐕❤️

🏥 What Is the Cataract Surgery Process?

The first step is visiting your regular vet, who will assess your dog’s diabetes regulation. Well-managed diabetes is a requirement for surgery. From there, you'll be referred to a veterinary ophthalmologist. 🩺👁️

🔬 At the Ophthalmologist’s Office:

• Complete eye exam with special lighting 🔦
• Visual inspection of tapetum and lens 🧿
• ERG test and ultrasound if surgery is a candidate ⚙️

🛠️ Types of Cataract Surgery in Dogs

There are two main procedures:

• Lens Extraction: Larger incision, more inflammation, greater risk of leaving lens fragments behind 🔪
• Phacoemulsification: Preferred method, uses ultrasonic waves to dissolve lens material and suction it out. Smaller incision, quicker healing 💉

After removal, an artificial lens is usually placed to restore focus and clarity. 🧿✨

🧴 Post-Op Care for Cataract Surgery

Commitment is key. Aftercare typically includes:

• Elizabethan collar to prevent eye trauma 😿
• Anti-inflammatory eye drops (e.g., corticosteroids) for several weeks 💧
• Oral anti-inflammatories for comfort 💊
• Pupil-dilating drops for easier healing 👁️

⚠️ Potential Complications

While most surgeries are successful, complications can occur:

• 🌋 Long-term uveitis (more likely in diabetic patients)
• 🌫️ Clouding of lens capsule (laser treatable)
• 🌧️ Corneal swelling (may need 5% saline drops multiple times daily)
• 🩸 Bleeding inside the eye
• 💥 Glaucoma or increased eye pressure
• 🧨 Retinal detachment (especially in hypermature cataracts)

👁️ Do Both Eyes Need Surgery?

Not always. Restoring vision in just one eye can significantly improve your dog's quality of life. Discuss options with the ophthalmologist—especially if surgery on both eyes poses additional risk. 🐕👓

📱 Support for Diabetic Dogs

Cataract surgery in diabetic dogs can feel overwhelming. But with a clear diagnosis, proper care, and post-op support, many dogs regain vision and continue to thrive. 🐾🌟

Need help navigating your pet’s post-surgery recovery? Visit AskAVet.com or download the Ask A Vet App for 24/7 advice, reminders, and expert care. 📲🐶

✅ Summary & Key Takeaways

• Diabetic dogs often develop cataracts rapidly 🧬
• Kinostat may prevent cataracts—but only if used early 🚫
• Not all dogs are surgical candidates; ERG testing is crucial 🔍
• Post-op care is vital for surgical success 🩺
• Blind dogs can still live happy, normal lives 🐶

🐾 Final Thoughts from Dr Duncan Houston

With early monitoring and professional guidance, your diabetic dog doesn't have to face a future of total blindness. Whether you’re exploring surgery or managing a blind pet’s needs, the goal is always comfort, safety, and joy. 🌈

For ongoing guidance and personalized vet support, connect with our team through the Ask A Vet App or at AskAVet.com. We're here for you and your pet every step of the way. 🐕‍🦺💙