Collie Eye Anomaly - CEA
OverviewCEA is a common eye disorder caused by abnormalities found in layers of tissue under the retina of a dog’s eye. Essentially, it occurs when a layer of eye tissue at the back of they eye under the retina called the ‘choroid’ fails to develop normally; this choroid abnormality is referred to as Choroidal Hypoplasia.
According to ophthalmologists, an underdeveloped choroid appears pale and so translucent that blood vessels in those areas are visibly thin in appearance.
In most cases, CEA is present at birth and can be detected in pups as young as five to eight weeks of age.
Severity - 3
CEA has a moderate ‘degree of severity’. While it is not a fatal disease, impaired vision may decrease the quality of life for both you and your dog.
In its mildest form, a dog may only carry the physical attributes of the disorder, choroidal thinning, and while they may retain relatively normal vision their entire life, they can produce offspring with more severely affected vision, even if their own case is not serious.
In severe cases, affected dogs can experience complications like the presence of abnormal eye tissue or hemorrhaging blood vessels and the likelihood of the affected dog suffering total blindness is almost certain. In the most extreme case, retinal detachment can occur, when this occurs in both eyes, the dog is completely and irreversibly blind.
There is a relatively small window of opportunity for ophthalmologists to pick up the disease. After approximately three months it becomes very difficult even for medical experts to detect.
Sadly, just like for people, there is no treatment or cure for blindness in dogs.
Animal Network provides a DNA test that determines the genetic predisposition to CEA.
The Collie Eye Anomaly – Choroidal Hypoplasia is an autosomal recessive disease. A recessive phenotype (trait or disease) will only be expressed when two copies of the recessive gene variant are present. A direct gene test can detect whether a dog is clear, carrier or is affected by the disease.
A dog with two copies of the recessive gene variant is affected, they will express the phenotype and will pass a copy of the gene variant onto their offspring 100% of the time. A dog with one copy of the recessive gene variant is a carrier, they do not express the phenotype themselves, however they are will pass the gene variant onto their offspring 50% of the time. A dog that has does not have any copies of the recessive gene variant is clear, and will never produce affected offspring.
For an explanation of possible genetic status of offspring please refer to our fact sheet on Breeding strategies. ORDER A TEST
Breeds AffectedAustralian Shepherd
Nova Scotia Duck Tolling Retriever
Shetland Sheep Dog