You have just brought home a puppy from a herding breed and discovered that the health paperwork includes a CEA diagnosis. Or perhaps your puppy's ophthalmoscopic examination came back with findings you didn't expect. Either way, you're sitting across the consultation table from me — or reading this at midnight after an anxious internet search — and you have questions. I have spent nearly three decades answering these questions. Here are the twelve I hear most often, with honest answers that I hope will provide genuine reassurance where it's warranted and accurate guidance where you need it.
1. "Is my puppy going to go blind?"
In all likelihood, no. The majority of CEA-affected dogs have choroidal hypoplasia as their only finding, and this does not cause any visual impairment. The affected area is in the peripheral fundus, outside the central visual axis, and dogs with this finding maintain entirely normal vision throughout their lives.
The minority of affected dogs with colobomas face somewhat more uncertainty, as colobomas can predispose to retinal complications. But even most dogs with small colobomas maintain functional vision, and the risk of serious visual loss relates primarily to the size and location of the coloboma. Your veterinary ophthalmologist can give you specific guidance about your puppy's individual risk based on the grade of findings documented at examination.
2. "Does my dog know something is wrong with its eyes?"
No. Dogs with mild CEA have no experience of visual difficulty because they have no visual difficulty. They have never known different vision, so there is no subjective sense of impairment. Even dogs with more significant findings adapt so naturally to their visual world that they typically show no behavioural signs of awareness that their vision differs from other dogs.
3. "Will it get worse over time?"
For the structural changes themselves, generally no. The choroidal hypoplasia and colobomas that develop during foetal life are the product of a developmental failure that has already occurred. The underlying lesions do not typically progress — a grade 2 choroidal hypoplasia in a six-week-old puppy is almost always still a grade 2 finding in a six-year-old dog.
The exception is secondary complications. Dogs with large colobomas have ongoing risk of retinal detachment, which can develop suddenly at any point, particularly before two years of age. If your dog has significant colobomas, understanding the warning signs described in my article on retinal detachment recognition will help you respond quickly if a complication occurs.
4. "My puppy's breeder said it's 'just mild CEA' — is that true?"
It may well be. "Mild CEA" typically refers to choroidal hypoplasia without colobomas, which genuinely is a mild condition in functional terms. Most affected dogs from affected herding breeds have exactly this presentation — bilateral choroidal hypoplasia of modest extent with no impact on vision or quality of life.
What I would urge is that you verify this characterisation with the actual examination report. A statement that a finding is "mild" should be supported by documented grades and a description of findings by a board-certified veterinary ophthalmologist. If you have this documentation, excellent. If the assessment was informal or came from a general practice veterinarian without specialist ophthalmology training, a specialist consultation is worthwhile for your own certainty.
5. "Should I have bought a dog with CEA? Did the breeder do something wrong?"
This requires nuance. In breeds where the CEA mutation is extremely common — Rough Collies, Smooth Collies, Shetland Sheepdogs — it is genuinely difficult to find clear dogs without severely restricting the breeding gene pool. Many responsible breeders make informed decisions to breed carrier or even affected dogs to clear partners, producing puppies who may be carriers or affected but who are otherwise healthy, well-tempered, and from excellent lineages.
The question to ask is not "did this puppy test affected?" but "did the breeder test and disclose?" A responsible breeder should have ophthalmoscopic examination records and ideally genetic test results for both parents and puppies, and should have disclosed CEA status to you before purchase. Thoughtful breeding strategies can reduce affected puppy rates without excluding valuable genetics from the breed — this is what responsible breeders pursue.
If the breeder tested and disclosed, they acted responsibly. If they failed to test or withheld information, that is a different matter worth addressing directly with them.
6. "Do I need to do anything differently to care for my CEA-affected dog?"
For the vast majority of affected dogs with choroidal hypoplasia only: no. They require no special management, no dietary supplements, no restricted activities, and no more frequent veterinary attention than any other healthy dog. They are not fragile. They do not need to be wrapped in cotton wool.
Dogs with documented colobomas warrant annual ophthalmoscopic re-examinations to monitor for any secondary changes, and their owners should be educated about recognising signs of visual deterioration or eye discomfort. Dogs who have experienced retinal detachment require more intensive monitoring and management. My article on living with a CEA-affected dog covers practical day-to-day management in detail.
7. "Will this affect my puppy's ability to do agility / obedience / herding?"
Almost certainly not if your dog has mild disease. Dogs with choroidal hypoplasia compete successfully at the highest levels of agility, obedience, herding, and other dog sports without any visual limitation attributable to their CEA status. The condition simply does not affect the visual function relevant to these activities.
For dogs with more significant colobomas, a functional vision assessment before intensive training is reasonable, but the majority of these dogs also function normally for sporting and working purposes. More detail on working dog capabilities in my article on CEA and working dog roles.
8. "Can I breed my dog if it has CEA?"
This is a breeding ethics and strategy question rather than purely a medical one. A dog affected by CEA is not medically unsuitable for reproduction — CEA does not affect general health, fertility, or maternal or paternal capability. The question is whether breeding the dog is responsible given its genetic status and the risk of passing the condition to offspring.
My position: affected dogs with valuable genetics can be used in breeding programmes, but only when paired with genetically clear dogs and with full disclosure to puppy buyers. An affected dog bred to a clear dog produces only carrier offspring — no affected puppies. This is a defensible approach that preserves genetic diversity whilst preventing affected puppy production. What is not defensible is breeding affected to carrier or affected to affected pairings without careful consideration and full owner disclosure.
9. "My dog's genetic test says 'affected' but the vet said the eyes look normal. Who's right?"
Both. The genetic test detects the presence of two copies of the NHEJ1 mutation. The ophthalmoscopic examination may not detect visible lesions in adult dogs because of the "go normal" phenomenon — increasing retinal pigment with age can mask underlying choroidal changes. The genetic test is right that your dog is genetically affected; the examination is right that there are no visible lesions at the current examination. Understanding this distinction is one of the most important concepts in CEA management.
10. "Is there any treatment or supplement that can help?"
For mild CEA — choroidal hypoplasia only — there is nothing to treat and no evidence that any supplement modifies the condition. Save your money. For dogs with colobomas or those who have experienced complications, management decisions should be made with your veterinary ophthalmologist based on your dog's specific situation. No supplement reverses structural developmental abnormalities.
11. "Should I tell my pet insurer about the CEA diagnosis?"
Yes, always disclose known health conditions to your insurer. Failure to disclose a known pre-existing condition is a common ground for insurance claim denial. However, I would also encourage you to understand exactly what CEA means for your dog's likely health costs before assuming it creates substantial insurance risk. Most affected dogs with mild disease will have zero additional veterinary costs attributable to their CEA throughout their entire lives. Disclosure is important; disproportionate worry about insurance implications is not.
12. "Is CEA painful for my dog?"
No. Choroidal hypoplasia and colobomas are not painful conditions. They cause no discomfort to the dog. The only scenarios in which CEA-associated findings might cause pain are if complications such as retinal detachment lead to elevated intraocular pressure, or if haemorrhage or inflammation develops — but these are rare complications requiring specific treatment, not inherent features of the condition itself.
A Final Word of Reassurance
I have spent nearly thirty years examining herding breed eyes and delivering CEA diagnoses. The overwhelming majority of those conversations end the same way: with an owner who came in anxious leaving with the understanding that their dog is perfectly fine, will remain perfectly fine, and has a completely normal life ahead.
CEA is a genetic curiosity that became medically significant largely because of its extraordinarily high prevalence in affected breeds. The condition that the name suggests — anomalous eyes in a collie — is, for most dogs, exactly that: an anomaly visible through the ophthalmoscope that has no real-world impact on the dog sitting in front of you, wagging its tail and waiting to go home.
The comprehensive information across this site is intended to ensure that every dog with CEA gets accurate diagnosis, appropriate monitoring, and honest guidance. If your puppy has been diagnosed and you still have questions, the first step is a consultation with a board-certified veterinary ophthalmologist who can review the specific findings and provide individualised advice. General resources, however thorough, cannot replace professional assessment of your specific dog.