Collie Eye Anomaly

What is Collie Eye Anomaly?
More technically known as choroidal hypoplasia, Collie Eye Anomaly (CEA) is a hereditary eye disorder in which the choroid layer of the eye, which is responsible for blood circulation in the eye, is underdeveloped at birth and remains so. In mild cases, your dog will never exhibit any noticeable signs. In severe cases, which make up about 25 percent of affected dogs, there can be partial blindness as a result of retinal detachment in areas in which the choroid is especially thin.

How does my dog get Collie Eye Anomaly?
CEA is inherited as a recessive trait. The same gene, which has been identified in DNA studies, is responsible for both mild and severe cases.

How do I know if my dog has Collie Eye Anomaly?
You will probably not notice anything amiss with mild cases. Even severe cases may go undetected in everyday life, except that the dog may miss some thrown objects or give other hints of blind spots. Your veterinarian will be able to detect the problem but looking into your dog's eye with an ophthalmoscope. The undeveloped choroid will be so thin places that she can see the back wall of the eyeball through it. This is most easily seen at 5 to 8 weeks of age, before the adult pigment color develops and masks the abnormal spots. In more severe cases, puckering or pits can be seen around the optic nerve, and these areas can lead to retinal detachments and new but abnormal blood vessels that can cause bleeding within the eye.  A DNA test is available that can detect the presence of the genes that determine CEA, but the test cannot determine severity.

What can I do about Collie Eye Anomaly?
There is nothing you can do about CEA, but your veterinarian may need to treat secondary problems, such as retinal detachment, if they arise.

Is there anything I can do to prevent my dog from getting Collie Eye Anomaly?
Dogs of predisposed breeds should have a DNA test before breeding. A dog with mild CEA is just as likely to produce a dog with severe CEA, as the same gene is responsible for both. A dog with CEA can be bred to a dog cleared by DNA and produce unaffected, but carrier, puppies.

Are there certain breeds that get Collie Eye Anomaly more often?
A vast majority of rough and smooth Collies are affected. The condition is also seen, but at much lower incidence, in Border Collies, Australian Shepherds, Shetland Sheepdogs, and other herding dogs.