👁️ Collie Eye Anomaly in Dogs – A 2025 Vet’s Guide to Genetic Eye Conditions and Vision Loss

By Dr Duncan Houston, BVSc

🔍 What Is Collie Eye Anomaly (CEA)?

Collie Eye Anomaly (CEA) is an inherited eye disorder that affects both eyes (often unequally). It can lead to vision defects, retinal detachment, or even blindness. 🧬👁️

CEA results from genetic mutations that disrupt development of the retina and choroid—the blood vessel layer under the retina. Some abnormalities appear soon after birth and may even disappear with age, while others progress over time. 📈

🐶 Breeds Most Affected by CEA

• Rough and Smooth Collies
• Border Collies
• Australian Shepherds
• Shetland Sheepdogs
• Lancashire Heelers

It’s also seen in mixed breeds with collie heritage. 🐾

🧬 Inheritance Pattern

CEA is inherited in an autosomal recessive manner. This means:

• 📦 A dog with two copies of the mutation = affected
• 🔄 One copy = carrier, no symptoms
• 🚫 Two carriers can produce affected offspring

DNA testing can identify all three genetic states with 90–95% accuracy. 🧪

📋 Common CEA Abnormalities

1. 🧠 Choroidal Hypoplasia

• Most common CEA defect
• Poor development of choroid (blood supply) beneath retina
• Causes blind spots, especially in low light

2. 🌀 Retinal Detachment

• Can occur at any age
• May involve partial or full vision loss
• Recurrent bleeding in the eye can lead to glaucoma and pain

3. 🧫 Colobomas

• Bulges or cupped areas near the optic disc
• May lead to retinal detachment or blindness

4. 📉 Retinal Folds

• Folds occur when the retina is too large for the eye
• May disappear with age but are a CEA marker

5. 💉 Vascular Abnormalities

• Malformed or missing blood vessels in the eye

🔬 Diagnosing CEA

CEA is usually diagnosed during a screening eye exam with dilated pupils, performed by a veterinary ophthalmologist. This is best done between 5–12 weeks of age. Retinal folds may disappear with age, so early screening is essential. 🔎

🧪 Genetic Testing for CEA

DNA tests are available and recommended for breeding dogs. They can identify:

• ✅ Clear (no mutation)
• 🟡 Carrier (one mutation)
• 🔴 Affected (two mutations)

Puppies can be tested as long as they’re big enough to safely draw blood. Responsible breeders should test both parents and avoid breeding two carriers. 🧬

👨‍⚕️ Treatment Options

There is no cure for CEA itself, but some complications like retinal detachment may be treatable surgically. Dogs with mild forms of CEA often live full lives with little visual impairment. ✅

🔁 Managing CEA

• 👁️ Schedule routine ophthalmology checkups for affected dogs
• 💬 Consult a veterinary ophthalmologist if vision changes occur
• 💡 Prevent breeding of affected or carrier dogs to reduce CEA in the gene pool

📲 Ask A Vet for CEA Advice

Not sure if your puppy needs screening? Have questions about DNA testing or breeding choices? Use the Ask A Vet App or visit AskAVet.com to connect with expert veterinary help. 🐶📱

✅ Summary: Collie Eye Anomaly

• 🧬 Inherited condition affecting the retina and choroid
• 👁️ Common signs include colobomas, choroidal hypoplasia, retinal detachment
• 🔬 Diagnosed by eye exam before 12 weeks old
• 🧪 DNA testing helps reduce cases through selective breeding
• 👨‍⚕️ Most dogs with CEA live full, comfortable lives

💬 Final Words from Dr Duncan Houston

CEA is a genetic condition—but it’s one that responsible screening, breeding, and care can manage. Whether your dog is affected, a carrier, or simply at risk, we’re here to help you navigate diagnosis, testing, and care. 🐾💙

Still have questions? Open the Ask A Vet App or visit AskAVet.com for fast, personalized guidance. 🩺📱