👁️ Cataracts in Dogs and Cats – A 2025 Vet’s Guide to Diagnosis, Surgery & Long-Term Care

By Dr Duncan Houston, BVSc

🔍 What Is a Cataract?

A cataract is an opacity or clouding in the lens of the eye that interferes with light passing through and reduces vision. Cataracts may affect a portion or the entire lens. In advanced cases, they cause full blindness. 🧬

🔬 Anatomy of the Lens

• 📍 Located just inside the pupil
• 🔗 Suspended by fibers called zonules
• 🎯 Focuses images onto the retina like a camera lens
• 🧴 Enclosed in a capsule—disruption can trigger immune inflammation

⚠️ Cataract vs. Nuclear Sclerosis

Older pets often develop nuclear sclerosis—a normal, age-related cloudiness from fiber compaction in the lens. Unlike cataracts, nuclear sclerosis does not cause blindness. Your vet can distinguish between them during an eye exam. 🧑‍⚕️

🐶 Cataracts in Diabetic Dogs

One of the most common causes of cataracts in dogs is diabetes mellitus. When blood glucose rises, excess sugar in the eye fluid is converted into sorbitol, drawing in water and clouding the lens. This can lead to rapid blindness, often within weeks. 💧

🐱 Do Diabetic Cats Get Cataracts?

No. Cats have alternative sugar metabolism pathways and do not typically develop diabetic cataracts. 😺

⚠️ Why Cataracts Are a Problem

• 🧱 Vision loss or blindness (partial or complete)
• 🌀 Lens luxation – the lens slips and blocks fluid drainage
• ⚡ Glaucoma – increased eye pressure due to fluid backup
• 🔥 Uveitis – inflammation from dissolving cataracts

🔍 Diagnosing Cataracts

• 👁️ Eye exam and visual inspection
• 🔦 Look for blockage of the tapetum (reflective layer at the back of the eye)
• 🧪 ERG (electroretinogram) and ultrasound before surgery

🧪 Cataract Classifications

• Young: <10% visual impact
• Early Immature: 10–50%
• Late Immature: 51–99%
• Mature: 100% visual blockage
• Hypermature: Lens begins dissolving—can cause inflammation

💊 Can Eye Drops Dissolve Cataracts?

⚠️ No. Products claiming to dissolve cataracts do not work. N-acetylcarnosine drops may be antioxidants, but they do not reverse cataracts. Delaying surgery while using these drops may worsen the outcome. ❌

🏥 When Is Surgery Needed?

Surgery is considered if:

• 👁️ Cataracts significantly impair vision
• 🔥 Inflammation is under control
• 🐶 Pet is in good health and cooperative with post-op care

Pets with one functioning eye may not need surgery unless the other eye causes discomfort. 🎯

🔧 Cataract Surgery Options

1. 🛠️ Lens Extraction

• Larger incision
• More post-op inflammation
• Used in older or dense lenses

2. 💡 Phacoemulsification (Preferred)

• 💥 Ultrasonic tool liquefies the lens
• 🧹 Vacuum tool removes debris
• 🔍 Smaller incision, faster healing

After either procedure, an artificial lens implant is usually placed to improve visual clarity. 🧿

📋 Pre-Surgery Evaluation

• 🧪 ERG test to check for retinal function
• 🔍 Ultrasound to check for detachment or other eye diseases
• 🩺 Blood tests and diabetes regulation

🛡️ Aftercare and Home Management

• 🩹 Elizabethan collar for 3 weeks
• 💧 Cortisone eye drops for several months
• 👀 Pupil-dilating drops
• 🐾 Switch to a harness to reduce pressure on the head
• 📅 Follow-up eye exams as scheduled

⚠️ Possible Complications

• 🔥 Persistent uveitis
• 🌫️ Capsule opacity (may require further surgery)
• 🩸 Bleeding (can result from post-op stress or barking)
• 📈 Glaucoma (especially with long surgeries or dissolving cataracts)

📈 Success Rates

95% of pets regain vision immediately after surgery; 80% maintain long-term visual success. 👁️✅

👁️ What If the Cataract Isn’t Treated?

• 🤍 Vision loss is not painful
• 😕 Some dogs adapt well; others become anxious
• 🔥 Inflammation must be treated to avoid pain and further damage

📲 Ask A Vet for Eye Surgery Support

Not sure if your pet needs cataract surgery? Want help managing blindness at home? Connect with the Ask A Vet App or visit AskAVet.com for expert guidance. 🐶📱

✅ Summary: Cataracts in Dogs and Cats

• 👁️ Cataracts block light and cause vision loss
• 📊 Diabetic dogs are especially at risk
• 🧬 Not all lens cloudiness is a cataract (nuclear sclerosis is harmless)
• 🛠️ Surgery is effective if the eye is healthy
• ⚠️ Surgery is invasive and requires commitment

💬 Final Words from Dr Duncan Houston

Cataracts are more than just cloudy eyes—they can mean blindness, inflammation, or even glaucoma. But with early detection, accurate diagnosis, and the right care, your dog or cat has a great chance at comfort and restored vision. 🐾💙

Reach out through the Ask A Vet App or at AskAVet.com for help navigating surgery, home care, or managing blindness. We’re here for every step. 🩺🐶